Serena WilliamsSerena Williams of the U.S.A. kept the U.S. Open trophy on home-turf for the fourth time in her career on Sunday with a hard-fought win over World No. 1, Victoria Azarenka of Belarus. Final score: 6-2, 2-6, 7-5.

Williams, who is ranked No. 4, won the match at 2 hours and 18 minutes, the longest  lasting match since 1981, and the first match to go three sets since 1995, giving the fans their money’s worth.

It was not a match to leave early, thinking it was all but over. It came down to the wire, with Williams digging deep into her mental reserves to climb back from a 3-5 deficit in the final set to claim the victory and her 15th overall major title.

After Williams won the first set easily at 6-2, it looked like Azarenka didn’t have a chance. But it was not the same Williams in the 2nd set. She looked a little listless and Azarenka was determined, taking the set with two breaks at 6-2.

Azarenka played tough the final set, and served for the match at 5-4. Williams broke back winning the final four games of the match bringing the 23,771 fans in Arthur Ashed Stadium to their feet.

When Azarenka’s final backhand sailed long Williams fell flat on her back, dropped her racket and covered her face with her hands. Then she got up, leaped several times in the air on her way to shake hands at the net.

“Oh my god,” said Williams in her on-court speech. “I honestly can’t believe I won. I really was preparing my runner-up speech, because I thought, ‘Man, she’s playing so great.’ ”

Azarenka, who will remain No. 1 in the world despite the loss, won the Australian Open in January during a 26-match winning streak to open the season.

“Serena deserves the win. She showed how true of a champion she is,” Azarenka said. “I definitely gave it all today. Stepping out of this court today, I will have no regrets… For me she is the greatest player of all time. She took the game to the next level.”

It was as great comeback for Williams, who had a nearly yearlong absence in June 2011 from a series of injuries and medical scares, including two foot surgeries and a hematoma in her stomach. Now, at age 30 when most have already retired from the pro circuit, Williams is playing some of her best tennis ever.

She became the first woman to win Wimbledon and the U.S. Open in the same year since she did it back in 2002.

She won her very first major championship at age 17 at the 1999 U.S. Open. Winning titles 13 years apart at the same Grand Slam tournament represents the longest span of success in the professional era, which began in 1968. Martina Navratilova (Wimbledon, 1978 and 1990) and Chris Evert (French Open, 1974 and 1986) had the longest previous spans of 12 years.

She turns 31 this month, and is the first 30-year-old woman woman to win the U.S. Open since Navartilova in 1987, and she shows no sign of slowing down.