Taylor Fritz defeated Alexander Zverev 6-3, 7-6 (4) on Sunday to clinch the Laver Cup for Team World.
According to ESPN, the American started strong at San Francisco's Chase Center before Zverev found his rhythm and mounted a late comeback in the second set.
But Fritz matched the intensity, holding firm to close out the match and secure victory.
"We're going to have a fun night," Fritz told ATP.com before the trophy ceremony. "Definitely popping some champagne in the locker room in a few minutes."
The win delivered the cup to Team World's Andre Agassi in his first tournament as captain, marking the team's third triumph in four years.
"Just seeing these guys on the bench getting pumped up, seeing a legend of the sport like Andre jumping out of his seat cheering for me, it's impossible not to be so fired up and just give it everything you have," Fritz said.
Earlier, Carlos Alcaraz kept Team Europe's hopes alive with a 6-2, 6-1 win over Argentina's Francisco Cerundolo.
The win cut Team World's lead to 12-9 in the first-to-13 event, where each Sunday match was worth three points.
Australia's Alex de Minaur had previously moved Team World within one point of the title, defeating Jakub Mensik 6-3, 6-4.
