John McEnroe claims he could beat Serena Williams at 56
John McEnroe has boasted he could beat women's world number one Serena Williams.
McEnroe, 56, made his claim in an interview on the Jimmy Kimmel Live chat show in the United States, and left the door open for a match against Williams in the future.
Tennis has seen previous matches dubbed Battle of the Sexes, most notably in 1973 when Billie Jean King, at the height of her career, defeated 55-year-old Bobby Riggs in Houston.
And when McEnroe was asked by presenter Kimmel if he could beat Williams, who will complete a rare calendar Grand Slam if she wins the US Open next month, he expressed confidence.
"My daughters are over there," McEnroe said. "I think it's mixed, they think I'd probably lose to Serena. I believe that I could still take her."
McEnroe recalled a previous offer to take on Williams, 33, who he rates as the greatest woman player of all time.
"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 fart 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."
And McEnroe then raised the prospect of a big-money showdown - equating the interest it would generate to the year's big welterweight boxing bout between Floyd Mayweather and Manny Pacquiao.
"So if they paid the kind of money that Mayweather and that other guy got ....," he said, before being interrupted.
The three-time Wimbledon and four-time US Open champion added: "I don't think I could take her in the (boxing) ring."