LONDON — Andy Roddick stayed on track for his fifth title at Queen's Club by defeating Ivo Karlovic 7-6, 7-6 today, advancing to the semifinals of the Aegon Championships.

Top-seeded Andy Murray lost just five points on his serve in beating American Mardy Fish 7-5, 6-3.

The second-seeded Roddick had 24 aces and Karlovic 26 in a match that featured few rallies and only two break points. Those came with Roddick leading 6-5 in the second set, but the Croat volleyed a winner on the first and hit a drop shot on the second.

Juan Carlos Ferrero reached his first career grass-court semifinal when he defeated Steve Darcis 4-6, 6-3, 6-4.

In Saturday's semifinals, Murray will play Ferrero. Roddick will face James Blake or Mikhail Youzhny, who played later.

Murray never faced a break point against Fish, and broke for a 6-5 lead in the first set after Fish netted a forehand volley.

Murray broke again to go up 4-3 in the second after Fish netted a backhand, and he sealed the match with a crosscourt winner.

Ferrero, who received a wild card to Wimbledon, had failed to advance beyond the quarterfinals on grass on three previous occasions.