Sifan Hassan's quest for a trio of world titles went up in smoke Saturday as she fell within sight of the finish line to hand Ethiopian rival Gudaf Tsegay victory in the 10,000m.
What had been a generally sedate race at the National Athletics Centre culminated in a sensational finish.
At the bell for the final 400 metres, Hassan made her move, going wide to reel in the front runners and take the lead with 200m remaining.
Tsegay and defending champion Letesenbet Gidey stuck with her into the final straight, the raucous crowd getting to their feet as Tsegay and Hassan broke away.
A grimacing Hassan, eyes fixed on the big screen at the end of the track, drifted wide from her inside lane in a bid to put off Tsegay, twice hitting the Ethiopian in the chest with her elbow.
Tsegay, however, rode the attempted obstruction and it quickly became apparent that it was in fact Hassan who had overcooked her desperate attempt to reach the line first.
The Ethiopian-born Dutch runner lost her footing and dramatically stumbled to the track amid gasps of disbelief.
As Hassan writhed on the track, so Gidey and third Ethiopian, Ejgayehu Taye, roared past her to seal a cleansweep for the east African distance running powerhouse.
- 'Keeping my smile' -
Tsegay, who won in 31min 27.18sec, was quick to cross back over the finish line to embrace Hassan, consoling her and helping her walk back.
"I am keeping my smile but it is really hard. I am very disappointed," said Hassan.
"This is sport, these things happen. I just had a bad moment. I felt really strong and tried to push in the last lap.
"I think I got pushed by the Ethiopian. I hope I am not crazy. I will need to look at the replay to see what exactly happened."
Hassan added: "I do not think I am injured. My hand is OK but the knee needs to be checked. Hopefully, all is good."
The fall put a quick end to Hassan's plan for a repeat of her unprecedented triple at the Tokyo Olympics.
She won gold medals in both the 5,000m and 10,000m and a bronze in the 1500m in the Japanese capital.
Despite a gruelling schedule, Hassan will now have to focus all her attention on the 5,000m and the 1500m, having run a heat in the latter earlier on Saturday.
The race had started in a predictable manner.
Hassan and Gidey were happy to bide their time at the back of the pack as a slow pace marked the first half of the 25-lap race.
The pace increased through to the final 10 laps, with Tsegay taking up the lead and the pack breaking up.
Hassan, tucked back in 12th place, stuck with the pace as Gidey and Taye went through a series of surges to further thin the field out.
Team tactics showed as the three Kenyans also came together, with the field packed with fast finishers.
The pack was reduced to 10 as Taye led with four laps to run, Hassan eventually making her move towards one of the most dramatic endings in world championship history.
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