Madrid - Defending champion Andy Murray advanced to the quarterfinals of the Madrid Open on Thursday by beating Tommy Robredo of Spain 7-5, 6-1.
Murray had failed to convert seven break points before finally getting the decisive breakthrough to go up 6-5 and then held serve to take the first set.
"I was a little tense when I had my chances and didn't take them," Murray said.
Murray, who turns 22 on Friday, then began hitting long, accurate baseline shots and well-timed passers to dominate the second.
"I noticed that at this altitude the ball tends to fly faster, and because the court is sprayed with water regularly the balls also tend to pick up weight," Murray said. "I strung my rackets more tightly to compensate and was happy to be able to control the ball in the wind here."
The 16th-seeded Robredo said he simply couldn't recover after giving up an early break in the second set.
"If you don't take your chances when you've got them, then he's going to kill you," Robredo said. "When you attack him he defends well, and if you let him attack he really does it."
On the women's side, Alona Bondarenko of Ukraine defeated Anna Chakvetadze of Russia, 6-0, 2-6, 6-3.
Later Thursday, top-ranked Rafael Nadal will Philipp Kohlschreiber of Germany, and women's No. 1 Dinara Safina faces Lucie Safarova of the Czech Republic.
Second-ranked Roger Federer takes on 14th-seeded James Blake of the United States.