Melbourne: An agitated Andy Murray was at his muttering, tormented best before reaching a higher plain to trounce Spaniard Feliciano Lopez 7-6 (7-2) 6-4 6-2 and advance to the Australian Open fourth round on Saturday.

The scorching heat that plagued Melbourne Park all week had given way to a pleasantly cool summer`s day but the moody Briton fumed and berated himself throughout the opening two sets at Hisense Arena as he struggled with his backhand.

However, on surrendering the second set, 26th seed Lopez`s resolve crumbled, allowing the 26-year-old Scot to coast to an encouraging victory in 135 minutes.

Fourth seed Murray, a three-times finalist at Melbourne Park, will next play French lucky loser Stephane Robert for a place in the quarter finals.