Federer battles back to take victory

Roger Federer came from two sets to love down to see off Tomas Berdych and reach the quarter-finals of the Australian Open.

Federer, who has won every one of their previous seven meetings since losing to Berdych at the 2004 Olympics, took three hours 29 minutes to get past the 20th seed and book a last-eight date with Juan Martin Del Potro.