Roger Federer Calls Serena Williams 'the Greatest Tennis Player of All Time' — Male or Female

From one tennis legend to another!

Tennis great Roger Federer opened up about his beloved sport in a candid interview for WSJ. Magazine‘s June/July issue — and the athlete couldn’t help but gush over another legend in the sport: Serena Williams.

“It’s been fascinating to watch,” he told the publication of Williams’ decades-long career. “She had a totally different upbringing — I came up through Switzerland with the federation, she did it with her dad and her sister. It’s an amazing story unto itself — and then she became one of the greatest, if not the greatest tennis player of all time.”

When asked if he meant she was the greatest female tennis player of all time, Federer clarified that he meant the greatest “overall.”

Tennis fans have often compared Williams and Federer, as both boast impressive stats. Federer has amassed 20 grand slam titles and Williams has earned 23. (Williams recently returned to the sport after a 14-month absence due to the birth of her daughter).

Federer, 36, noted that the tennis world has changed since the earlier generations, mentioning Billie Jean King and Rod Laver. But he says Williams, 36, is up there with them all.

“We know [Serena] is all the way up there. I’m probably up there with somebody, somehow. Maybe there’s a group, a best of five — and if you’re in that group, you should be pleased and happy. Tennis is a funky sport when it comes to that stuff,” he said.

“I’m in full admiration of Serena. And Venus, too, by the way.”

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Williams later weighed in on Federer’s G.O.A.T. comments, dishing out some praise for her fellow tennis great.

“I think we can say that about both of us, respectively,” she said.

“He’s done amazing things in his career — I have the utmost respect for him. He’s a wonderful athlete, a great guy. I love what he’s doing [with his foundation] in Africa too. That was really impressive to me.”