Sixth seed Nikolay Davydenko, who has beaten Federer in their past two meetings, kept alive the possibility of another encounter in the quarterfinals by beating German qualifier Dieter Kindlmann 6-1 6-0 6-3.
Their cause has been led by a rare group of all-time players in their prime: Roger Federer (who is president of the ATP World Tour's player council), Rafael Nadal, Novak Djokovic and Andy Murray.