MELBOURNE (Reuters) - Andy Murray, berating himself for playing "nonsense" tennis in the second set, overcame pesky practice partner Ricardas Berankis on Saturday to advance to the fourth round of the Australian Open.

The third-seeded Briton struggled to break down the stubborn 22-year-old and grew frustrated with himself throughout the match, sporadically breaking into outbursts of anger between games before he ran out a 6-3 6-4 7-5 victor.

Murray and Berankis have practiced together several times in Australia over the past two years and the Lithuanian qualifier exploited that knowledge to change his pace, shots and angles to effect Murray's timing.

U.S. Open champion Murray, who sealed the two hour, 12 minute victory when Berankis's service return smashed into the net, will now meet either 14th-seed Gilles Simon or Gael Monfils in the last 16. The French duo clash later on Saturday.

(Reporting by Greg Stutchbury; Editing by Patrick Johnston)