Last night Federer and his partner Nicolas Mahut beat Grigor Dimitrov and Jeremy Chardy in straight sets.
At one point during the match, Federer completely mishit an overhead. But it deflected off the frame of his racket with such backspin that it landed on Dimitrov/Chardy's side of the net and then spun back over the net for a winner.
The rare unintentionally incredible Federer shot (via Larry Brown Sports):