Roger Federer beats Serena Williams in doubles match

Jan. 1 (UPI) -- Tennis icons Roger Federer and Serena Williams matched up for the first time on Tuesday, with Federer earning a victory in a mixed doubles match in Australia.

Federer and partner Belinda Bencic beat Williams and partner Frances Tiafoe 4-2, 4-3(3) in the matchup between Switzerland and the United States at the Hopman Cup in Perth.

"I was nervous returning," Federer said in his on-court interview. "People talk about her serve so much and I see why it is such a wonderful serve because you just can't read it," Federer said. "It was great fun. You see how determined and focused she is, and I love that about her."

"GOAT vs. GOAT," Williams posted on Instagram, using the emojis for the acronym for Greatest of all-time. "The GOAT won."

Starting 2019 with a bang @rogerfederer @FTiafoe #HopmanCup pic.twitter.com/kFZAdBc4pw

— Hopman Cup (@hopmancup) January 1, 2019

The 37-year-olds each won their respective singles matches. Federer and Bencic earned a 2-1 win in the round-robin mixed doubles tie.

"It was a great experience," Williams said while alongside Federer. "I'm kinda sad it's over. I was just warming up."

Federer and Williams have combined for 43 Grand Slam singles titles.

Smiles all around as the Swiss secure victory!@rogerfederer and @BelindaBencic defeat Serena Williams and Frances Tiafoe 4-2 4-3(3).@Channel9 @9Gem | #HopmanCup pic.twitter.com/iG015tS827

— Hopman Cup (@hopmancup) January 1, 2019

The 2019 Australian Open is the next Grand Slam on the tennis slate. The tournament begins on Jan. 14 in Melbourne.