British teenager Andy Murray blew a second set lead to lose 6-3, 7-6 to Croatia's Mario Ancic in the second round of the Auckland Open on Wednesday.

Murray was leading 5-3 in the second set but a double fault gave his Croatian opponent an opening and the world number 21 took full advantage to progress to the last eight.

"I don't normally let leads like that slip away," Murray told reporters. "I had chances. He is obviously a very good player and has a lot of experience."

Ancic, a Wimbledon semi-finalist, was impressed with what he saw of Murray.

"It was a very tough second round draw and it could have gone either way," he said.

"I was a little bit rough with my game in the second set, but I came back well. I think it was a good match for the crowd.

"From 5-3 I played much more aggressively. I started to win points by myself, not waiting for his mistakes."

Sixth seed Olivier Rochus of Belgium beat Czech qualifier Jan Hernych 6-1, 7-5 to set up a quarter-final against Spanish second seed David Ferrer, who beat Dutchman Raemon Sluiter 6-4, 6-3.

Seventh seed Jarkko Nieminen of Finland beat American Paul Goldstein 6-4, 6-3 while Switzerland's Stanislas Wawrinka beat Alberto Martin of Spain 6-2, 6-2.