Juan Martin del Potro stood with his hands on his knees, exhausted from taking the mightiest swings he could with his ferocious forehand.
Novak Djokovic kept getting the ball back, so del Potro would take a bigger whack, trying to find some spot in the corner of the court that would be uncovered.
That eventually wore him out and led to mistakes, and del Potro lost 6-3, 7-6 (4), 6-3 on Sunday in the final of the U.S. Open, the tournament he most wants to win again.
But just getting back, hearing those delirious Argentine fans sing "Ole! Ole! DelPo!" again between points, gave him something else rewarding to take home from Flushing Meadows.
"What I said on the stage, you can lose or win a trophy, but the love from the crowd, it could be even bigger than the tournament," del Potro said. "That's what I got from them. It will be in the heart for the rest of the life."
It wasn't long ago he never knew if he would hear that sound again. He nearly quit tennis in 2015, after four wrist surgeries that wouldn't let him regain the form that carried him past Roger Federer to win the 2009 U.S. Open.
The powerful player couldn't hit the ball hard enough with his backhand to threaten top players, let alone the rulers of the sport like Federer, Djokovic and Rafael Nadal. But del Potro not only stuck with it, he surged up to a career-high No. 3 in the rankings last month on the strength of a semifinal run at the French Open and a victory over Federer to win Indian Wells.
Djokovic said he believes del Potro will win another major title.
"With his wrist injuries, with coming back and still having faith, having belief in himself that one day he's going to be a top player and he's going to be fighting for Grand Slams," Djokovic said, "I really wish him all the best."
The quest to win a second major will have to wait until next year, but del Potro, who turns 30 this month, feels good about his chances with the way his wrist held up over the last two weeks.
"I will keep playing tennis for a few more years," he said. "I don't know when will be my last tournament in this career, but I'm excited to keep surprising myself doing things like this. I'm very motivated to keep trying to win these titles."
He was in tears afterward, with both Djokovic and John McEnroe coming over to give him a consoling pat on the shoulder as he sat on his chair waiting for the trophy presentation. He was drained from 3 hours, 16 minutes trying to find weaknesses in perhaps the best defender in tennis, especially after losing the 22-point, 20-plus minute game in the second set that was the match's pivotal moment.
Del Potro might have beaten other players Sunday, same as some of the losses to Federer and Nadal through the years may have been victories against lesser foes.
Some two hours after the match, del Potro walked out to the players garden to a greeting from his group of about a dozen friends who have led the cheers from his box, supporters from back home he has credited with keeping his spirits up during the depressing days when he was injured.
Beloved in Argentina and embraced in New York, he's looking forward to resuming his chase next year.
"I'm just doing my job, trying to be an example for the kids, to teach them that you have to do effort to get your goals in your life," del Potro said.
"I will try to keeping (troubling) these guys, playing in the next tournaments, and we'll see."