It was the tennis showdown of the century!

On Tuesday, Roger Federer and Serena Williams, both 37, played each other for the first time in a doubles match at the Hopman Cup in Australia, according to the Associated Press. In front of a crowd of 14,000, Federer, representing Switzerland, took the court with Belinda Benic and beat Williams, who played alongside Frances Tiafoe, five games to three, the BBC reported.

After the match, the athletes — who have 43 Grand Slam titles between the two of them — took a selfie on the court. The mother of one posted the sweet picture to her Instagram with the caption: “Goat vs Goat. The Goat won.” She used the goat emoji as a stand-in for the acronym GOAT, meaning “Greatest of All Time.”

Federer also posted the image, writing, “Oh what a night,” alongside the tennis ball and fire emojis.

According to USA Today, the athletes raved about each other at the end of the match-up.

“What a pleasure. What an honor,” Federer said, the outlet reported. “It was nerve-wracking, too. I thought, ‘I’ve got to win this point but it is Serena Williams.’ People talk about her serve so much, and I see why it is such a wonderful serve because you just can’t read it.”

Williams added, “It was a great experience … I’m sorry it had to finish. I was just warming up. It was such fun, we grew up together. It was super cool … This guy is great, both off the court and on the court. I think his serve is super-underestimated. It’s a killer serve, you can’t read it. I watched him all the time, and I never knew how amazing it was.”

She also shared that she wished she had the opportunity to introduce her daughter, Alexis Olympia Ohanian Jr., 16 months, to the sports superstar.

“I wanted to take pictures and bring my baby out,” Williams said.

Even though it’s the first time they’ve been on the same court, it’s not the first time they’ve spoken so highly of each other. In a candid interview for WSJ. Magazine‘s June/July issue this year, Federer praised Williams.

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“[Her career has] been fascinating to watch,” he told the publication. “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.”

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

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Williams later weighed in on Federer’s comments, asserting that he also has earned GOAT status.

“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,” she said.

According to BBC, Switzerland, who won the cup last year, will play Greece on Thursday in their final round-robin match, and the USA will take on Great Britain.