2015 U.S. Open - Day 10"All the single ladies" also includes Justin Timberlake and Jimmy Fallon!

The singer and late night host are longtime friends who attended last night's U.S. Open match between Roger Federer and Richard Gasquet. They were hanging out before their sixth "History of Rap" collaboration aired on "The Tonight Show."

While they were watching the quarterfinals match from the Emirates Suite box, Beyoncé's song "Single Ladies" began playing in Arthur Ashe Stadium. That prompted the besties to get up and follow along with the famous choreography:

The dance delighted the crowd and proved to be a good omen for Federer, who easily won the match in straight sets. And Timberlake and Fallon have achieved #peakbromancegoals.

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