Alistair Brownlee beat brother Jonny as they repeated last year’s achievement of a British one-two at the World Series Triathlon event in their home city of Leeds.
The duo opened up a sizeable gap in the cycle before Olympic champion Alistair ran clear with 2.5km left to win in one hour, 46 minutes and 51 seconds.
Jonny crossed the line 12secs later with Spain’s Fernando Alarza third.
Bermuda’s Flora Duffy produced a superb display to win the women’s race.
The 29-year-old, who triumphed in the World Series event in Yokohama last month, dominated the race, winning in a time of one hour, 57 minutes and two seconds.
America’s Taylor Spivey was second, 1min 30secs behind Duffy, with Italy’s Alice Betto third.
Brilliant Brownlees too good for the rest
For the first time in a World Series triathlon event, four of the top five finishers were from the same country, thanks to Britain’s Tom Bishop and Adam Bowden, who finished fourth and fifth respectively.
Once again, though, the Brownlees dominated in their first race together since Alistair carried stricken Jonny over the line in last year’s World Series finale in Cozumel in Mexico.
They were among the first out of the water, in a field that did not contain world champion Mario Mola or Javier Gomez, and were part of the lead group on the bike leg alongside Pierre Le Corre and Aurelien Raphael before breaking away from the French pair after the first 10km.
The gap was more than a minute when they began the run, during which Alistair again showed his superiority.
“It was really special,” Alistair told BBC Sport. “You can never expect to win a race and know what is going to happen.
“I was involved in it from the very start, bidding to get it here and doing some course organisation. The last few hundred metres leading up to Millennium Square was amazing. I will remember this experience for the rest of my career.
“We were riding really hard on the bikes. For the first three laps of the circuit, we were probably riding as hard as we ever have. That took it out of us on the run.”
Jonny said: “It was a hard way to do that race, to be the two of us from the end of the swim.
“If I want to beat Alistair, that is not the way to do it. I basically turned it into a long-distance hard man’s race and he is a bit harder than me.
“We wanted people to work with us but they weren’t strong enough. I was feeling good at the start of the run but injuries and illnesses mean I have missed quite a lot of training this year.”
Alarza heads the World Series rankings with 2,743 points, 679 ahead of compatriot Mola.
Three-time British Triathlon champion Annie Emmerson, speaking to BBC Sport
It is one of the best races I have ever seen. What those guys do – coming into town and staying away from that bike pack, which was literally 10 lengths behind – is amazing.
It was the Brownlee show. For all these guys that have come out here today, they have made it special.
Once again, though, Alistair has shown that he is just the best that there is.
Britons struggle in women’s race
Jessica Learmonth was the highest-placed Briton in the women’s race, with a World Series personal best of sixth after a final surge took her past Australia’s Gillian Backhouse.
The Leeds-born athlete was leading during the cycle, but dropped back to help team-mate Non Stanford.
“We spoke before the race and that was the tactic [to work as a team],” Learmonth told BBC Sport. “I was more than happy to drop back and help Non push on. It is something we need to practice and this is a great place to do it.”
Welsh former world champion Stanford finished 11th.
“It wasn’t my best time,” she said. “I have had a rough couple of weeks since Yokohama. I gave it as much as I could for as long as possible, but when I got to the run I had nothing left.
“We decided we were going to work as a team and that Jess would wait, so I did everything I could to get back up to her after the swim and to get us in a good position but I don’t think I contributed very much, unfortunately.
“It is just a matter of getting myself round and the crowds helped me do that. I know it is a cliche but the support was fantastic.”
The women’s World Series rankings are led by American Kirsten Kasper, who finished fourth on Sunday and now has 2,049 points, 175 more than compatriot Katie Zaferes.
Team GB triathlete Vicky Holland, speaking to BBC Sport
These guys [Jessica and Non] are my team-mates and friends so I know when they have had troubles and injuries and illnesses and setbacks. I don’t think there is a single person in the team today who has had a smooth run-in.
These two gave it everything. There is no doubt what they put into the race. Jess did a great job and went back for Non.
The front group were working together, motivated well by Flora Duffy, and the gap kept growing as they were motivated by the podiums.