Roger Federer reached his 50th Grand Slam quarter-final in London today with a 6-4, 6-2, 6-4 win over Grigor Dimitrov in the Wimbledon fourth round. Seven-time Wimbledon champion Federer will face eitherCanada's Milos Raonic, the sixth seed, or German 10th seedAlexander Zverev for a place in the semi-finals. Federer, 35, is also the second oldest man to make thequarter-finals at Wimbledon behind Ken Rosewall who was 39when he reached the last-eight in 1971.