Justin Timberlake was sitting courtside at the Pacers-Heat game, where he watched Danny Granger sing "Holy Grail" for his teammates, who had to guess which song he was singing in order for a lucky fan in the audience to win a pair of headphones. Once Justin and the rest of the crowd figured out what Granger was singing, he stood up and gave the baller a standing ovation for attempting to belt out the tune. Check out the comedic performance in the above slide: