Transcript for Roger Federer defeats Serena Williams in doubles battle

Thank you so much. We move on to an historic meeting. Roger Federer and Serena Williams, two of the greatest players of all time facing off for the first time in a mixed doubles match and T.J. Is here with how it went down. Reporter: Good morning to you. How cool was this. We're talking about the greatest tennis player of all time on the court and Roger Federer happened to be there as well. This was not some international friendly, right? This was a real competition and what a treat to see Serena and fed go at it for real. The game's greatest ever stars greet each other. Reporter: Roger Federer and Serena Williams, the greatest tennis players on the planet. Head-to-head for the first time. The two went at it in a mixed doubles match in Australia. I was nervous returning because you just don't know. People talk about her serve so much and I see why it is such a wonderful serve because you can't read it. You don't see until -- I can't read yours either. Reporter: The match is a new take on that famous 1973 battle of the sexes. It's been a night I think that was not expected by most. Reporter: With Billie Jean king taking down Bobby Riggs. Being crowned the greatest ever regardless of gender is always a hot topic but even Federer, the 20-time grand slam champ chimed in in may telling Wall Street magazine that Williams is one of the greatest if not the greatest tennis player of all time. Federer and his doubles partner Belinda bencic defeated Serena and her Passer in Frances tiafoe. He is the greatest of all time to be honest. And both on the court and off the court. Reporter: But no hard feelings after this one. They capped off the match with a hug and a selfie. Of course. So no hard feelings there and, look, it wasn't the one-on-one we'd like to see but they couldn't handle each other's serve. Neither one so that was cool to see but bragging rights, look, Federer's team won but if they lined up trophies she will have three extra than he has in his line. I thought they were so respectful of each other. Yeah. They were enjoying this moment. It was a treat to both of them to be on court. Treat for us to see it.

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