American tennis player Danielle Collins embraced the Australian Open boos after her latest win. But there's more to her heel turn than meets the eye.

Count Novak Djokovic as being in Danielle Collins' corner. He thinks her response to booing fans at the Australian Open was absolutely fine — which should come as no surprise, given the way Djokovic gets into back-and-forths with hecklers at his matches,

Danielle Collins has long been one of women's tennis' most fiery competitors. But after her tight second-round Australian Open win over Australian underdog Destanee Aiava, Collins showed she can bring it with the crowd,