Williams jumping up and down on the tennis court with a wide smile across her face.

Williams picking up a major title — this time, the U.S. Open trophy, which will look good alongside the gold medals she won at the Olympics and the silver plate she took home from Wimbledon.

If there was anything unexpected about her latest triumph, it was the challenge she faced from Victoria Azarenka, especially considering the way Williams dominated everyone she faced on the way to Sunday’s final, to say nothing of the way the final started.

Come the third set, with the sun going down and the stadium completely blanketed in shadows, Williams stood only two points away from a loss. She rediscovered her form in time, took the last four games of the match and won her fourth title at Flushing Meadows and 15th Grand Slam title overall with a 2-6, 6-2, 7-5 victory. It was the first women’s U.S. Open final to go three sets since 1995.

“If it was anybody other than Serena on the other side of the court, I’m not sure we’d be talking now,” said Patrick Mouratoglou, a coach who has been working with Williams recently. “But it was Serena. She was there. She’s a winner and she’s a champion.”

Mouratoglou helped Williams engineer a restoration that began shortly after she lost in the first round of the French Open in May, the only opening-round exit of her 49 career Grand Slam appearances.

“She said, ‘I want to win Wimbledon, I want to start now,’” Mouratoglou said. “That’s simple. That’s how it started.”

Since then, Williams won both singles and doubles at Wimbledon, then matched that feat a month later at the London Olympics.

The U.S. Open was the clincher — a two-week clinic during which she lost only 19 games over her first six matches, then put on a display in how to play pressure tennis when the stakes were the highest. Trailing 5-3 and serving at 30-all against Azarenka, the Australian Open champion seeded first in this tournament, Williams wrested back control of the match by winning 10 of the next 12 points.

“Obviously, I never give up,” Williams said. “I never, never quit. I’ve come back so many times in so many matches. I wasn’t too nervous.”

Indeed, for a woman who has had her share of flare-ups here in recent years, Williams barely showed a trace of emotion when this match was at its diciest. There was the smallest of hesitations for a second look after a serve was called out at 3-5, 30-15. And, when she closed out that game three points later, she did the quickest of skips — a nearly imperceptible celebration before a calm walk to the chair to get ready for the service break she had to have.

She got it, then held serve, and then twice held off Azarenka when she was one point from forcing a third-set tiebreaker. The first save came on a backhand winner, one of 44 winners Williams hit to only 13 for her counterpunching, but less powerful, opponent.

“Feels like there is no room for a mistake,” Azarenka said in describing what it’s like dealing with Williams’ game. “There is no room for a wrong decision.”

Williams hasn’t always played the role of cool customer in Arthur Ashe Stadium.

In the 2009 semifinals, she was angered by a foot-fault call that resulted in a double-fault, setting up match point for her opponent, Kim Clijsters. Williams brandished her racket at the line judge and got docked match point. Then, two years later, while losing to Sam Stosur in the 2011 final, Williams berated the chair umpire after losing a point for screaming before it had ended.

There was a foot-fault call in this match, too, while Williams was serving at 40-0 while trailing 2-0 in the second set. She didn’t react immediately, but when the game was over, she stared down the lineman while walking to her chair for the changeover. The linesman chuckled a bit. No biggie.

“I’m just happy that she got through this one without any incident and was able to try to forget all that in the past,” said her mom, Oracene Price. “Because I think that was a lot in her mind.”

Also on Williams’ mind this summer has been her long journey back.

Shortly after winning Wimbledon in 2010, she cut her feet on broken glass while on her way out of a restaurant in Germany. That led to two operations on her right foot. Later, she got clots in her lungs and needed to inject herself with a blood thinner. Those shots led to a pool of blood gathering under her stomach’s skin, requiring another procedure in the hospital.

By the time all that was over, she had been off tour for about 10 months. She returned in 2011.

“She was so disgusted at home. She felt like she was useless. That’s the way it is with athletes, I guess. She couldn’t sit still,” Price said. “She was getting depressed. A lot to overcome.”

She did overcome it, and now she adds another championship to the best resume currently in the game.

She is the first woman to win Wimbledon and the U.S. Open in the same season since 2002, which is when she last did it.

She moved three Grand Slam titles away from a tie for fourth on the all-time list with Martina Navratilova and Chris Evert.

Navratilova was the last thirty-something to win the U.S. Open. Williams, who turns 31 on Sept. 26, joins her on that list.

But Williams does not play, act or talk like a woman nearing the end of her career.

There are a few tournaments to be played this fall on hard court. The next Grand Slam season starts in January in Australia. Williams said “my motivation is up there,” and those who know her feel it, too.

“She’s very, very motivated and feels she can win every tournament,” Mouratoglou said. “If one day she doesn’t feel the same, we’ll see, but for the moment, she feels she can win every tournament she plays, which is true, she can. So, she’s prepared to do everything to do it.”