Dutch woman Sifan Hassan's dream of an unprecedented treble looked under threat on Monday as she tumbled and fell in her 1,500 metres heat but she recovered brilliantly and pushed hard to win her race and advance to the semi-finals.
Hassan, a 5,000m world bronze medallist and world champion in the 1,500m and 10,000m, confirmed on Sunday that she will bid to win medals in all three races, in what would be an Olympic first.
It didn't go smoothly for her on Monday. At the start of the last lap of her 1,500m run, she got tangled up with Kenya's Edinah Jebitok, who had just tripped and gone to ground in front of her.
Hassan fell but quickly picked herself up and pushed hard, running from 11th with 600m remaining, to win in 4:05.17, her resilience ensuring she qualified for Wednesday's semi-finals.
The Ethiopian-born 28-year-old will have to recover quickly as she is scheduled to run in the 5,000m final on Monday night.
A major rival for gold, the defending Olympic champion, Kenya's Faith Kipyegon, easily won her 1,500m heat with a dominant performance that paved her path to the semi-final, keeping her on track to retain the title she won five years ago in Rio.
Kenya successfully appealed after Jebitok's fall and she will be in semis. Other qualifiers from Monday's 1,500m heats include Britain's Laura Muir, who came second in her heat to advance. Muir, who had also contemplated running in the 800m, said she will withdraw from the shorter distance.
"I'd hate to be mediocre at both and, while it was emotionally a tough decision to make, mentally it was clear to me that the 1500m is where I needed to be," she told BBC Sport.
Canada's Gabriela Debues-Stafford, who finished ahead of Muir on Monday, ran a controlled race to win her heat with a time of 4:03.70.
"I wasn't expecting it to be that fast," she said after the race. "I'm very pleased with that."
