Abu Dhabi - South African triathlete Henri Schoeman became only the second man in world series history to win a race after leading out of the swim, bike and run on Friday.
In the women's race, Rachel Klamer became the first Dutch triathlete - female or male - to top a world series podium.
Schoeman's six-second victory in the season-opening Abu Dhabi race was only his second in the world series, after the Cozumel Grand Final in 2016.
He made his move on the third lap of the bike, riding the last 10km solo and taking a 13-second lead into the run.
Unseasonal rain made the bike ride on part of the Formula One track slick, and several racers crashed, including Jonathan Brownlee, who resumed cautiously and finished seventh.
"I was telling myself that if they catch me on the run, well, whatever, because I had fun on the bike and I was safe," Schoeman said.
Second was Mario Mola of Spain, the Abu Dhabi winner in 2015 and 2016. Vincent Luis of France was third in a repeat of 2017.
Bike crashes forced the withdrawals of women's world champion Flora Duffy, fellow American Katie Zaferes, and Joanna Brown of Canada.
The Americans were among the leading pack of 11 on the bike, which dropped to four on the run. Klamer broke away on the last lap and won by 14 seconds.
"There was no way I was expecting this," Klamer said. "I was quite scared on the bike because the last few months I have been training on only straight roads and didn't do any corners. There was a lot of women crashing so I just decided to take it easy, ride hard, but just go easy through the corners."
Jessica Learmonth of Britain was second and Natalie Van Coevorden of Australia was given third in a photo finish with Kirsten Kasper of the US.
The second race in the series is in Bermuda on April 28-29.