After Team World’s triumph over Roger Federer's star-studded Team Europe to win the Laver Cup, Frances Tiafoe, the last player to arrive, befitting his reputation in the locker room, strolled into the post-match news conference and yelled, "Champs are here!"

Then the 24-year-old from Maryland joined his teammates at the table where the silver trophy was resting Sunday night, put down a bottle of water, pulled a Budweiser out of his red jacket and smiled that wide smile of his.

Performing with the same infectious showmanship and crunch-time success he displayed en route to his first Grand Slam semifinal at the U.S. Open earlier this month, Tiafoe staved off four match points and came back to beat Stefanos Tsitsipas 1-6, 7-6 (11), 10-8, giving Team World its first triumph in five editions of an event founded by Federer's management company.

"I don’t like losing," said Federer, a 20-time major champion whose final match before retirement was a loss alongside Rafael Nadal in doubles against Tiafoe and Jack Sock on Friday night. "It’s not fun. It just leaves not the best taste."

When Tsitsipas put a forehand into the net to end Sunday's contest - and the three-day competition - Tiafoe dropped his racket and fell to his back on the court, where teammates piled atop him. After getting on his feet, Tiafoe cupped a hand to his ear, asking spectators for more noise, then pointed to his chest and yelled, "I'm him! I'm him!"

"When it becomes a circus out here, and I'm just using the crowd and acting like a little kid and having a bunch of reactions ... I end up playing really well and I start building momentum off it," Tiafoe said. "I’m able to play and function in that better than my opponents, it seems."

Using the nickname other players gave Tiafoe to reflect the way he embraces big moments, Team World captain John McEnroe said: "Frances is ‘Prime Time.’ He loves this stuff."

McEnroe had been 0-4 while leading his squad against his former playing rival, Team Europe captain Bjorn Borg; both indicated they would be back for the 2023 Laver Cup in Vancouver, but that might be their last go-round.

This one served as a celebration of Federer and the 41-year-old Swiss star’s career.

Tiafoe responded with a quip when asked whether he might owe Federer some form of "I'm sorry" for beating him in his finale or for defeating his team, which also included Nadal, Novak Djokovic and Andy Murray for a total of 66 major singles titles. That, incidentally, is 66 more than Team World, a collection of 20-somethings (Sock turned 30 on Saturday).

''I’m not going to apologize to him. He’s got a lot to apologize for after the last 24 years - after beating everybody on the tour," said Tiafoe, who went 0-3 against Federer in singles head-to-head. "I will say thank you for having me in this amazing event, what he’s done for the game. He’s a class act. Happy to know him, happy to call him a friend, happy to call him a colleague, and best wishes in his second act. But I will not apologize."

Team Europe entered Sunday at O2 Arena with an 8-4 lead; the first team to 13 points would win.

Each match on Day 3 was worth three points, and Team World went ahead thanks to a pair of victories by Felix Auger-Aliassime, a 22 year old from Canada. He beat Djokovic 6-3, 7-6 (3), after partnering with Sock to edge Murray and Matteo Berrettini 2-6, 6-3, 10-8 in doubles.

Tiafoe then made it 13-8, but it wasn't easy.

He went a tournament-record 8-0 in tiebreakers at Flushing Meadows this month and was just as resilient Sunday.

"It’s been a long time that Frances has been playing the big guys close and losing a lot of close battles. It’s great to see lately he’s been winning," said Taylor Fritz, an American who is the same age as Tiafoe and has known him for years. "It’s about time that he steps up and the matches go the other way. Today was a joke."

That's because Tiafoe was a single point from losing to Tsitsipas four times in their second-set tiebreaker, but somehow got through that. Then, at 4-all in the concluding match tiebreaker - first to 10, win by two - Tiafoe sprinted from behind the baseline to near the net and barely got to a drop shot by Tsitsipas, somehow lunging to flick an angled winner.

While most of the 16,365 fans went wild, Tiafoe went around the net and stood still, hands on his hips, relishing the atmosphere.

"We put him in the slot that he was in today for a reason," said Team World's Tommy Paul, another 24 year old American, "and he stepped up for us, big time.