Britain's Jonny Brownlee beat his brother Alistair into second place at the World Triathlon Series in Hamburg.
The pair were challenged by Spain's Javier Gomez on the run before kicking for home, with Jonny Brownlee outsprinting Olympic champion Alistair.
Jonny Brownlee has now won three races, to two from Alistair and one for Gomez, in an interrupted post-Olympic season.
Germany's Anne Haug put in a powerful finish to beat Britain's Non Stanford and Jodie Stimpson in the women's race.
Saturday was the first time since London 2012 the three men's Olympic medallists had competed together in the same race.
The Hamburg event was over the shorter sprint distance with a 5km closing run, rather than the Olympic distance of 10km.
"I always thought I had a better sprint," said Jonny Brownlee, 23. "I thought if I didn't beat him today I'd probably never beat him. We got to the last bit and he came past me but I was feeling quite comfortable."
Alistair Brownlee, 25, said: "What a great race. To be honest, the aim for me was to be in the hunt and I was more than happy to be in it at the last corner. I think I went a bit early."
He added: "I knew I wasn't running that well. I thought I was hanging on for third place; I was hanging on for dear life."
Gomez leads the overall standings on 2,965 points, with Jonny (2,400) and Alistair Brownlee (2,340) in fifth and sixth respectively after missing a number of races.
Each winner of a World Series event gets 800 points, second place 740 and third 685, while higher points are on offer in the Grand Final, with the victor picking up 1,200 points.
The champion is decided based on competitors' best four World Series finishes plus their Grand Final result.
In the women's race, Haug kicked for home with 800m remaining and her British rivals could not respond, with Stanford outsprinting Stimpson to take second place.
"I'm absolutely delighted," said Wales' Stanford. "When Annie went she was amazing. I really tried to go with her but didn't have the legs. I was happy to hang on for second."
England's Stimpson, who trains alongside Haug, said: "We're from different countries but we're team-mates at the end of the day, and it's great to be out there racing with her."
The British pair had won the previous two rounds of the World Series, with Stimpson victorious last time out in Kitzbuehel after Stanford won in Madrid.
Haug leads the standings on 3,025 points after six of the eight rounds, with Stimpson second (2,855), American Gwen Jorgensen third (2,775) and Stanford in fourth (2,528).
The next round of the Word Series takes place in Stockholm on 24-25 August before the Grand Final over the Olympic course in London's Hyde Park on 11-15 September.