Andy Murray has admitted that he is expecting a "tough" match when he takes on Grigor Dimitrov in the fourth round of the Australian Open.

The British number one beat Portugal's Joao Sousa in straight sets earlier to set up a meeting with the Bulgarian, who knocked him out of Wimbledon last year.

The world number six told reporters: "It will be a tough match. He's played well in the Slams the last year or so. He's a talented player.

"He's one of the young guys trying to make a breakthrough, so he'll be motivated. Hopefully I can play a good match and make it tough for him."

Murray has reached at least the quarter-finals in Melbourne every year since 2010.