The women's Olympic triathlon saw chaotic scenes with multiple crashes during the cycling section of the event in Paris.
The build-up to the race had been dominated by concerns over water quality in the River Seine.
Organisers gave both the men's and women's races the green light on Wednesday morning, avoiding the 'last resort' possibility for the events to become duathlons.
Athletes in the women's race, however, were more impacted by the slick road surface during the cycling section of the event following rain in the French capital.
The conditions contributed to several crashes which led to a number of withdrawals from the race.
Several crashes impacted athletes during the women's Olympic triathlon in Paris
Norway's Lotte Miller was among the athletes to suffer crashes during the bike section
Miller eventually withdrew from the race after twice crashing on the slick road surface
Guam's Manami Iijima was the first athlete to crash, with Brazil's Vittoria Lopes, Germany's Lisa Tertsch and Belgium's Jolien Vermeylen also impacted by an incident.
Home favourite Leonie Periault was also impacted, along with Colombia's Maria Carolina Velasquez Soto.
Lotte Miller crashed twice during the bike leg, with the second incident leading to the Norwegian pulling out of the race.
Germany's Laura Lindemann saw her hopes of a podium finish heavily impacted when she fell with three laps remaining of the bike leg.
Lindemann had been part of a 10-rider leading group, but dropped off the pace following her crash.
'Laura Lindemann didn't do a lot wrong there, she is a good, strong, very technical rider,' former British triathlete Annie Emerson said on the BBC.
'There is grease on the road and that is causing the upsets that we have seen in the race.
'I don't remember a race where I have seen so many athletes go down.'
Guam's Manami Iijima was the first triathlete to suffer a crash during the women's race
Iijima was one of four athletes forced to pull out of the race amid a series of incidents
Former British triathlete Annie Emerson believed the greasy road surface had contributed
Britain's Beth Potter and Georgia Taylor-Brown avoided crashes during the bike section and entered the run in the leading group.
The men's race will follow on Wednesday morning after organisers were forced to postpone the event on Tuesday over water quality issues.
A statement from Paris 2024 and World Triathlon early on Wednesday confirmed water quality tests had shown a drop in bacteria levels.
The statement said: 'The results of the latest water analyses, received at 3.20am, have been assessed as compliant by World Triathlon allowing for the triathlon competitions to take place.'
World Triathlon also posted a picture of the River Seine on social media, writing 'We will swim'.
Swimming training for the triathletes was cancelled on Sunday and Monday after water quality testing.
Organisers gave the green light on Wednesday morning for triathlon races to take place
Triathletes took to the River Seine with water quality deemed to have improved sufficiently
More than a billion euros was spent on cleaning up the river in preparation for the Games, but organisers knew heavy rain in the days before a competition could cause the levels of the harmful bacteria E. Coli to rise.
Swimming in the Seine, which dissects the city, has been banned since 1923.
In 1990, Jacques Chirac, then mayor of Paris, famously declared that he would make it clean enough to enter, but failed in his mission.
Earlier this month, following astonishing investment, current mayor Anne Hidalgo plunged in with a group of around 100 officials and swam around 100 metres.