All Serena Williams needs is love!

The Beatles ‘all you need is love’ holds true for the US Open champion and World No 1 Serena Williams.

Williams admits that having love in her life has been a key to her rousing success over an exhilarating 13 months in which she has won Olympic gold, two US Open titles and a French Open.

Following a fitful night's sleep after winning her fifth US Open crown on Sunday in a three-set thriller over world number two Victoria Azarenka, Williams surprised a small group of reporters when asked about the power of love.

"Love? I think it's important to have it in your life, I guess. I'm not an expert on that subject," said Williams, whose stellar run coincides with her partnership with French coach Patrick Mouratoglou, who has also been linked romantically with the American World No 1.

"Everyone says you get one. Some people say you get two. I'm definitely in love with tennis right now," Williams, a towering figure in crystal spike heels adorned in gold rhinestones and wearing a black blazer over a mini-dress, added coyly with a smile.

Williams, who will turn 32 later this month, became the oldest women's winner of the US Open since tennis turned professional in 1968 when she claimed her fifth US Open title.

The American World No 1 said she was having too much fun and success to contemplate leaving the tennis stage.

"I haven't thought of a number or age when I'm going to stop. I can tell you this: I don't see myself retiring any time soon and obviously there's some goals that I want to reach and things that I want to do."

Her latest US Open triumph increased Williams' haul of Grand Slam singles trophies to 17, one behind Chris Evert and Martina Navratilova, and five behind Steffi Graf. Australian Margaret Court rules the record books with 24.

As she moves up the all-time list, Williams has become aware of how she compares with the greatest players ever.

"I definitely want to continue to focus on Grand Slams and put the work into doing that," said Williams, who said she increased her tournament-load this past year, winning nine titles, in order to reclaim the world's top ranking.

"I just really am enjoying myself," she said. "This year I've played a lot more. I'm happy about that too, but I'm having a lot of fun."

Williams, who also played doubles with her older sister Venus at Flushing Meadows, may have shown her age in how she approached her celebration of the latest grand slam triumph.

"I had a little room service and I went to sleep. I was really tired," said Williams in a gravelly voice after just three hours of sleep.

"I had a long two weeks, with the doubles and the terrible scheduling at times. It wasn't very easy, so I was happy it was all over."

Williams looked full of life on the court in her two-week US Open run, overwhelming opponents on her way to the final.

She looked poised to make Azarenka her seventh successive straight-sets victim when she was serving for the match twice in the second set, before she admittedly "tightened up" and was forced to a tiebreaker won by the battling Belarussian.

Williams said that despite all her success, she has a tendency to get more nervous now than earlier in her triumphant Grand Slam career, which was launched with a victory at age 17 at the 1999 US Open.

"When you're playing for something different you start to think about it too much," Williams said, hinting at the history she is chasing with each additional Grand Slam win.

"That's what happened to me a little bit in the second set. I started to think way too much. But in the third, I just didn't care.

"I was just like 'this is what's going to happen, this is what I'm going to do and this is going to be the result,'" added Williams, who closed out the third set 6-1.

Williams said experience has taught her the importance of balancing two opposing elements required for her on-court success.

She said being "fierce" on the court was critical, but just as important was tempering that fiery emotion with composure.

"I'm better at being calm, more relaxed," said Williams, who still wears emotion on her sleeve in the glare of big matches, screaming at herself, gesturing and muttering in an interior dialogue to find the right mix of calm and fire.

Fitness at the relatively advanced age of nearly 32 is not an issue.

"I feel like jumping down and doing one-armed push-ups right now," the muscular Williams said, drawing laughs from the reporters. "But I can't, by the way."