Great Britain lived up to their billing as favourites to win the Team World Championship ahead of hosts Switzerland on a hot day in Lausanne.
The Brownlee brothers both shone, with Jonathan - crowned solo world sprint champion on Saturday - aggressively putting GB ahead on the second leg.
Alistair clinched the victory on the last leg, 14 seconds clear.
World-leading Welshwoman Helen Jenkins and Jodie Stimpson completed a British "dream team" in difficult conditions.
Jenkins, who heads the women's individual world rankings with just one event of seven remaining, said: "It was really tough, but it was fun to race as a team for a change."
On a day when temperatures soared beyond 33C, with a high level of humidity, Jonathan Brownlee agreed with his team-mate.
"It was a hard race, short and fast," he added. "The Swiss team are really strong but it was great fun."
After Stimpson's solid start, the younger Brownlee brother leapt into Lake Geneva for the 265m swim 16 seconds behind leaders Germany.
But after a superb transition following a fine 5km cycle, he snatched the lead to sprint away during the 1.2km, with France's Vincent Luis on his shoulder.
Jenkins opened up a 14-second lead after her swim and, cycling and running alone, she managed to stave off a chasing pack of three to ensure Alistair Brownlee took over 11 seconds ahead of Switzerland.
Brownlee duly coped with the intensity of the heat, and the level of competition, to such an extent that he started his running leg with a 21-second lead, which allowed him to cruise home with relative ease.