19 January 2013 Last updated at 12:10

Australian Open 2013: Andy Murray hopes he has more in the tank

Britain's Andy Murray admits he did not play his best tennis in his scrappy third-round Australian Open win, but believes a player's performance should improve as a tournament progresses.

The third seed saw off Lithuanian Ricardas Berankis 6-3 6-4 7-5 on the Rod Laver Arena, and will now face either Gilles Simon or Gael Monfils, both from France, in the last 16.

Murray says he will need to up his game for either opponent, and describes Monfils as "the best athlete ever" in tennis.