Roger Federer receives standing ovation when spotted court-side at Brooklyn Nets NBA game in New York

Swiss tennis legend Roger Federer sent basketball fans into a frenzy as he attended the game between the Boston Celtics and the Brooklyn Nets at the Barclays Center in Brooklyn.

Nets reporters Kristina Winfield and Adam Himmelsbach attested to the warm reception the tennis legend received from the NBA crowd. The audience rocked the stadium with their loud cheers for the 20-time Grand Slam champion.

"Roger Federer may have just set the record for loudest applause for a celebrity at Barclays Center this season," wrote Winfield of the New York Daily News on Twitter.

"Loudest ovation of the day goes to Roger Federer, who's courtside," said Himmelsbach of The Boston Globe.

Federer waved as he was shown on the jumbotron, the words "tennis legend" written under his name.

New York has been a witness to the retired tennis star's legendary career as he lifted five straight US Open trophies there from 2004 to 2008.

The Brooklyn Nets posted about their special visitor on Instagram.

"Greatness in the building," the NBA team wrote.

A photo of the well-loved sports hero beaming and a short video clip of him as he sat court-side accompanied the post.

The Swiss Maestro expressed his gratitude via an Instagram story.

"Always a pleasure. Thanks for having me, Brooklyn" wrote the former World No. 1.