Murray will face third-seeded Mikhail Youzhny, who moved into the semifinals when Philipp Kohlschreiber retired with fatigue after losing the first set 6-4.

Tursunov pressured Murray from the beginning and won the first set after a break in the fifth game.

Murray saved two break points in the fifth game of the second set — and two more in the ninth — before forcing a tiebreaker.

In the third, Murray saved three break points in the sixth game and broke the 27th-ranked Russian in the next game.

Youzhny, the 2004 champion, won four consecutive games to rally from 2-4 down to win the first set.

At that point, Kohlschreiber decided not to continue the match. The German said he was taking aspirins and antibiotics after feeling sick since Tuesday. He retired from his second straight tournament.

"Towards the end of the first set I started feeling more and more powerless and tired," Kohlschreiber said.