Manchester City Carlos Tevez cheering on Juan Martin del Potro at the O2 Arena.
Del Potro defeated Roger Federer 6-3, 6-7, 6-3 but confusion over the complicated scoring system over who had qualified for semi finals of the ATP World Tour Finals means he have to wait for official final decision.
After the confusion is clear, Del Potro invite Tevez - who was watching court-side, to take part in an impromptu knock around tennis with him:
Tevez awaring that tennis is harder than what it looks like for him, he resorted to keepy-uppies to give spectactors something to cheer.
Enjoy the highlights between Juan Martin del Potro and Roger Federer:
