Caeleb Dressel collected his eighth career Olympic gold medal, and a first of the Paris Games for the U.S. team, when he anchored them to a second successive 4×100 meter freestyle title on Saturday.
Australia took silver and Italy the bronze, with China missing out on the medals in fourth place.
Jack Alexy, Chris Giuliano, Hunter Armstrong and Dressel combined in a time of three minutes 09.28 seconds to beat Australia by 1.07 in the last final of a raucous opening night at the La Defense Arena.
Matt King and Ryan Held swam in the morning heats but were switched out in favor of Alexy and Giuliano for the final. King and Held will also receive gold medals.
Dressel won five golds at Tokyo in 2021 and two in Rio de Janeiro in 2016.
In the women’s 4×100, Australia made it 2-for-2 against its rivals from the U.S., claiming their fourth straight Olympic title in that event.
The quartet of Mollie O’Callaghan, Shayna Jack, Emma McKeon and Meg Harris set an Olympic record with a winning time of 3:28.92.
The Americans — Kate Douglass, Gretchen Walsh, Torri Huske and Simone Manuel — rallied to take silver in 3:30.20. They edged China’s team of Yang Junxuan, Cheng Yujie, Zhang Yufei and Wu Qingfeng by a tenth of a second.
Reuters and The Associated Press contributed to this report.