Novak Djokovic is known as one of the nicest - and funniest - guys on the tour and he bust out another top impersonation on Sunday to do that burgeoning reputation no harm.
The only thing was, he was impersonating his coach, Boris Becker. We're not sure how Sir Alex Ferguson would have reacted if David Beckham did similar, or Jose Mourinho with Fernando Torres.
But Boris took it in excellent spirits and the whole crowd at the Aussie Open were enjoying it hugely.
Djokovic had just beaten Fabio Fognini in straight sets, 6-3, 6-0, 6-2, to advance to the quarter finals on the tournament.
So which Beckerism did Novak opt for - the over-the-top arching back-bend serve or the classic Becker diving volley?
You'll have the watch the clip to find out...