20: No more waiting (1983)
While it was Buster Watson who got proceedings in Helsinki's Olympic Stadium underway in earnest with a win in the first 100m heat, he wasn't the first to taste victory. The championship began the previous day on Sunday 7 August with the women's marathon. The late, great Norwegian Grete Waitz, having won the first edition of the women's London Marathon earlier in the year, topped the first ever World Championship podium in the first ever women's marathon run at an international championship. Four years before Waitz had become the first woman to break the 2:30 barrier, and she did so again with a 2:28:09, exactly three minutes ahead of American Marianne Dickerson, finishing off on the track.
19: Back to the top (2015)
Jessica Ennis-Hill produced a composed and consistent set of seven events to win her third heptathlon world title. The mountainous challenge confronting Ennis-Hill, having only returned to training in the autumn of 2014 after giving birth in July, was made that bit bigger as she battled her way back to competitive shape against an Achilles trouble. It was clear after day one that Ennis-Hill had overcome her problems and would be the athlete to beat as she topped proceedings heading into the final three events. Katarina Johnson-Thompson, her closest competitor on day one, fell away after no-marking in the long jump, so by the time she reached the 800m it was effectively two-lap victory ceremony.
18: Fraser-Pryce wins thrice (2013)
Shelly-Ann Fraser-Pryce was already a double Olympic champion over the 100m and two-time world champion from 2009, but Moscow fully cemented her status among the legendary female athletes. The Jamaican queen of sprinting matched Usain Bolt's achievements in Moscow, winning gold in each of the 100, 200 and 4x100m, making her the first female athlete to do so in a single World Championships. In the 100m she annihilated her competition, clocking 10.71 to miss equalling the championship record by one-hundredth of a second. The 200m saw Fraser-Pryce's biggest threat, Allyson Felix, pull up on the bend, allowing a free run to gold before she anchored the Jamaican women to what was at the time the second-fastest time ever.
17: Radcliffe's relief (2005)
Despite her pedigree among the greatest female distance runners of all-time, Paula Radcliffe hadn't managed to produce her best form at a major championships until Helsinki in 2005. Overcoming the heartbreak of the Athens Olympics the year before, Radcliffe toed the line of the marathon with a real point to prove. She led a group including defending champion Catherine Ndereba through the first half before increasing the pace between 25-30 kilometres. Turning the screw, Radcliffe opened the gap wider over the final third, eventually finishing more than a minute clear of Ndereba in a championship record 2:20:57. Finally, after all her past successes, Radcliffe could call herself world champion.
16: Lewis leads six sub-10s (1991)
Regarded by some as possibly the greatest sprint race of all-time, the Tokyo men's 100m final produced something which to this day has still yet to be bettered: six men running sub-10 times in one race. Recovering from a shocking start, Carl Lewis executed a characteristically strong back-end of the race to win gold. World record-holder Leroy Burrell stood in the way as the defending champion's biggest threat, having run 9.90 earlier in the season, and looked to have the race sewn up by 50 metres. Lewis worked his way through the field gradually overtaking Raymond Stewart, Frankie Fredericks, Linford Christie and Dennis Mitchell before edging ahead of Burrell to dip at 9.86. Burrell also bettered his former record with 9.88, while each of the aforementioned men also broke through the invisible barrier of speed.
15: The Flying Dutchwoman (2015)
A successful 2014 season convinced Dutch heptathlete Dafne Schippers that she should switch her energy full-time to sprinting, and it proved to be the best decision she ever made. Schippers had only run her first sub-11 100m time earlier in the year, but improved to make the podium in Beijing with a 10.81 national record for silver. The 100m was just a sign of things to come as Schippers was to produce a run for the ages in the 200m – her stronger of the two events. She found herself fourth as she entered the straight, trailing Jamaica's Elaine Thompson in first, but Schippers came to the fore in the latter stages, powering past Thompson and dipping well at the line for a championship record 21.63. The time placed her third on the all-time list and was the fastest non-altitude run in 27 years.
14: Moses rallies in Rome (1987)
The great Ed Moses had finally seen his 122-race winning streak broken by fellow American Danny Harris, though there would be no repeat in Rome. Harris and 1983 runner-up, Harald Schmid, were to push Moses as close as he ever had been in the final. The defending world and Olympic champion started off the race at speed and held a clear lead over the field by the second hurdle. He extended this further and worked a three-metre gap ahead of his chasing rivals into the home straight. The near-suicidal pace began to catch up with Moses who started slowing. Schmid and Harris homed in as the once-unbeatable American ran through treacle but their efforts were insufficient as Moses clung on for his toughest, most memorable of victories.
13: Two Mo' Medals (2015)
Mo Farah made yet more history in Beijing in becoming the first man ever to complete a 'triple-double' of distance titles. Yet again Farah was forced to think fast on his feet as he encountered a trio of Kenyan athletes in the 10,000m determined to knock him off his perch. Whittling the field down to just five as they entered the final lap, Farah's bid for a sixth straight major distance gold almost unravelled as he was tripped by Geoffrey Kamworor, but he recovered to pull away from the Kenyan and teammate Paul Tanui with a blistering sprint finish. In the 5000m it was Caleb Ndiku whose onus it was to break Farah's streak. He refused to allow the Briton the lead, upping the pace inside the final 1000 metres and leading, but the Kenyan couldn't find enough in the home straight to counter Farah's kick, leaving him to run free to create distance running history.
12: Johnson doubles down (1995)
Try as they might, no athlete has managed to match Michael Johnson's 200/400m double from the 1995 Gothenburg championships. Threatening both world records, Johnson was imperious in Sweden as he secured two championship records. Over the lap Johnson powered to 43.39 – to date the fourth fastest ever – though the look on his face was tinged with regret, having missed the world record he craved by 0.1 seconds. In the 200m he appeared happier, punching the air after clocking 19.79 as the only man to go sub-20. Just to add to his individual success, Johnson brought home a third gold, anchoring the US quartet in the final event in the Ullevi Stadium.
11: Jackson record leads British duo (1993)
Ten years after Colin Jackson burst into the senior international picture with a bronze in Helsinki, he was top of the world. Jackson entered the championships as world no.1, having run 12.97 into a headwind in the month before the Stuttgart World Championships and eyes were on him to see what he could achieve. The Welsh hurdler got off to a strong start and put on a technical masterclass of sprint hurdling to dip under the world record by one-hundredth of a second. Fellow Briton Tony Jarrett's silver medal finish in 13.00 meant it was the first time in a World Championships that the country had finished with gold and silver in the same event. Jackson's record of 12.91 was to last for 13 years.
10: Jumping Jackie (1987)
Jackie Joyner-Kersee was one of the unquestionable stars of 1987 in Rome as she produced two performances which still today are the best any World Championship has ever seen. During her day Joyner-Kersee was the best multi-eventer and long jumper on the planet, and she proved it yet again in Italy. Firstly, she wiped the floor with her competition in the heptathlon, topping the table in four of the seven events including a 7.14m long jump. Her final total of 7128 was the third best of her career at the time. Her best leap in the long jump at 7.36m was a personal best performance and beat Soviet jumper Yelena Belevskaya, who could only match the distance Joyner-Kersee achieved during the heptathlon.
9: Gunning for the record (1993)
British hurdlers dominated the landscape at the 1993 World Championships. The day before Colin Jackson flew to his world record Sally Gunnell had set the bar with one of her own. She entered the championships in Germany as reigning Olympic champion and had beaten American Sandra Farmer-Patrick in Barcelona with her superior strength over the final barriers. Gunnell had to dig deep to conjure up the same qualities in 1993 to win herself world gold and become only the second athlete to run under 53 seconds. Farmer-Patrick took it out fast and was ahead off the final barrier. Gunnell managed to maintain her form and stay in touch before finally overhauling Farmer-Patrick in the final steps in a time of 52.74.
8: Can't be B-Eaton (2015)
Beijing played host to the greatest decathlon ever witnessed as Ashton Eaton won a second world title, breaking his record in the process. Throughout two gruelling days Eaton was a man on a mission, and it was to be mission complete. Displaying an astonishing level of focus and consistency, highlighted by an outstanding 45.00 run over the 400m and holding a lead that even Michael Johnson would have been proud of, the 27-year-old was within touching distance once the 1500m came calling. Eaton knew it was going to take every ounce of effort over the course of a typically draining race to beat his score from 2012 and he mustered enough to do so, finishing with an all-time best performance of 9045 to beat his previous score by six points – equivalent to around 0.8 seconds in the 1500m.
7: Kostadinova raises the bar (1987)
Stefka Kostadinova's world record has this year stood for 30 years and it goes to show the significance of her achievement that even today doesn't look close to being beaten. She was at her best during the 1987 season, consistently clearing heights well in excess of 2.00m ahead of making her World Championship debut. When it came to it, not even defending champion Tamara Bykova of the Soviet Union was able to stand in her way. Bykova, with a best clearance at 2.04m – three centimetres higher than she needed for 1983 gold – was the only other athlete who went above 2.00m. The crowd were still in a frenzy having just watched a dramatic men's 100m final when Kostadinova served up something even better, sailing over 2.09m and breaking her own world record. To this date, only one athlete has ever matched her 2.08m previous record.
6: Quirot defies the odds (1995)
Ana Fidelia Quirot was left fighting for her life in 1993 after she was caught in an explosion at her home, resulting in horrific burns which requiring months of skin grafts as well as causing the sad premature birth and death of her daughter. Two years later, the Cuban 800m runner was top of the world. Adamant that the doctors' prognosis that she would likely never compete again Quirot planned her return from her hospital bed. In Gothenburg the Olympic bronze medallist saw her courage richly rewarded. Having qualified for the final Quirot watched as Letitia Vriesde of Suriname and Kelly Holmes of Great Britain set off at blistering speed. As the pair did battle for the lead down the back straight and round the top bend, Quirot waited before pouncing with 100 metres remaining, kicking through the gears and exploiting her greater short distance speed to kill off their challenge. Quirot's victory can be seen as a true triumph of human spirit.
5: Bolt vs Gatlin (2015)
Usain Bolt had never faced so many questions over his capacity to maintain a grip over world sprinting as he did in 2015. Battling fitness issues, Bolt found himself pressured to prove to those he had done so to so frequently over seven years that he had what it took to bring down a swaggering Justin Gatlin, who was enjoying a near-two-year unbeaten streak. The American former world and Olympic champion entered the championships as world no.1 over both the 100 and 200m, and cruised to the final in 9.77 while Bolt was left to struggle his way through in 9.96, just barely recovering from a slip in his blocks. When the final came round, Gatlin looked finally ready to triumph over his great rival. He held a lead over Bolt entering the final 20 metres but, sensing the imposing Jamaican breathing down his neck, began reaching for the line. Losing composure he allowed Bolt to sneak in, pipping him by 0.01 in 9.79 and offering a definitive answer to his detractors.
4: Edwards' record rush (1995)
World records came like London buses for Jonathan Edwards in Gothenburg. He had proven he was in the shape of his life ahead of the championships when he unleashed a colossal 18.43m wind-assisted jump in France. And Edwards didn't have to wait long to make the world record officially his. In the opening round of the 1995 final, Edwards became the first man to go out beyond 18 metres with a wind-legal leap with 18.16m. As if that wasn't good enough, the soon-to-be world champion went even further just 20 minutes later where, with his second-round jump, he flew out to 18.29m. The first was followed by an ebullient celebration but the second, simply by a sheepish grin as he came to terms with 20 life-changing moments. The final standings saw Edwards sitting top by 67 centimetres ahead of Brian Wellman.
3: Johnson's crowning glory (1999)
For some six years Michael Johnson had been banging on the door of Butch Reynolds 400m world record to no avail. The Seville 1999 World Championships, his last, was to be the scene of arguably his greatest accomplishment, six years after first winning the 400m title. Setting a new world record of 43.18 Johnson ran a time which for 17 years many believed to be untouchable. Johnson was the only athlete to qualify for the final in a sub-44 time and it was simply a matter of how fast he could go. Everyone else was left to joust for the minor medals. The American got out ahead of the field in the usual fashion and it was only once the stagger unwound on the home straight that Johnson's supremacy was clear for all to see. The American continued to open up a gap down the home straight as his competitors tired faster, and he crossed the line a clear 10 metres ahead, registering more than a second faster than Sanderlei Parella in second.
2: Mike Powell vs Carl Lewis (1991)
Mike Powell vs Carl Lewis in the 1991 long jump final goes down as the greatest contest seen at an IAAF World Championships and is up there in the conversation of the greatest head-to-head battles in sporting history. Heading into Tokyo Lewis boasted a 15-0 record over Powell, but the tables were to turn. Powell opened with a modest 7.85m and shortly after watched Lewis, the 100m world record-holder and double Olympic long jump champion, fly out to 8.68m – further than Powell's personal best. The underdog followed Lewis up by going out into second but he sat by to see his adversary fly out to 8.84m and then beyond Bob Beamon's 8.90m world record with a wind-assisted 8.91m. Lewis looked destined to break Bob Beamon's world record. Powell, though, would have the last laugh. In his penultimate jump he produced the jump of a lifetime, flying to 8.95m and a new record. Immediately after Lewis soared out to the longest wind-legal jump of his career – 8.87m which left Powell with an anxious wait during measurement – and out far again with his final effort, but not far enough. Lewis had produced to best set of jumps ever seen, but Powell had the record and the gold.
1: The fastest man ever (2009)
The notion of being the fastest resonates with most every man, woman and child, and Usain Bolt succeeded in doing the ultimate: being the fastest man in history. The Jamaican's world record-breaking feats over the 100 and 200m at the Beijing Olympics were done in such an astonishingly carefree manner – Bolt beat his chest en route to a 9.69 win in the 100m – that the anticipation was bubbling to see what he would do next in Berlin. Bolt delivered the same pre-race showmanship which had become his trademark and followed it with the two most outstanding sprint races ever seen. In the 100m, instead of the mid-race antics, Bolt worked towards something special over every metre, even dipping his head to win in 9.58 while Tyson Gay finished back in second in a previous record-equalling time. And the Jamaican wasn't done there. Having broken Michael Johnson's astonishing 19.32 200m world record in 2008, there was extra determination of Bolt's face as he roared his way through a perfect half-lap, shaving 0.11 off his own record to clock 19.19.
Wednesday 26 April marks 100 days to go until the 2017 IAAF World Championships. We are counting down the top 100 moments in the Championships history. Let us know your highlights on social media using #IAAF100.