LONDON • Tennis veteran John McEnroe has boasted that he can beat world No. 1 Serena Williams, even as she moves in on a calendar Grand Slam that has not been seen in the women's game in 27 years.

McEnroe, now 56, and with more than two decades behind him since winning his last Grand Slam, made the claim on American chat show Jimmy Kimmel Live.

He added that he would be banned from locker rooms if he lost to "God forbid, a woman".

His bold assertion comes as Williams, 23 years his junior, sets her sights on one more tournament victory to complete her set of all four Grand Slams in the tennis year.

Steffi Graf was the last woman to achieve the feat in 1988.

Williams needs to win the US Open at Flushing Meadows, New York next month to do the same.

During the interview with Kimmel, McEnroe said he believes Williams, who has 68 titles to her name, is the greatest female player of all time.

But when he was asked if he thought he could beat her now, he replied: "My daughters are over there, they think I'd probably lose to Serena. I believe that I could still take her."

McEnroe, who has 77 titles under his belt, including three Wimbledon wins, recalled that real-estate mogul Donald Trump - now a 2016 Republican US presidential candidate - had once offered to stage a match between him and Williams.

"Fifteen years ago, Donald Trump, who seems to be in the news a little bit, he made an offer that I felt like was not enough," McEnroe said. "I think he was humouring the two of us.

"Serena, she's got a lot to lose by losing to an old f**t like myself. And I've got a lot to lose, because if I lose to, God forbid, a woman, then I'm not allowed in any men's locker room for the next 15 years, or possibly the end of my life. So that's part of why it's intriguing."

McEnroe, who is regularly seen commentating on tennis tournaments, suggested a showdown between him and Williams would create a fever of interest similar to a boxing showdown between Floyd Mayweather and Manny Pacquiao.

"But I don't think I could take her in the ring," he added.

THE GUARDIAN