Roger Federer was playing Grigor Dimitrov in an exhibition match in New York's Madison Square Garden on Wednesday when this rather delightful moment occurred.
During the third set, Dimitrov decided to let someone else have a go and allowed this young boy to take to the court.
Federer, being the total pro he is, carried on as normal.
He even rushed to the net to put his opponent under pressure.
Which was a terrible mistake, because the young wizard simply lobbed the ball over the tennis legend's head to win the point.