Rafa Nadal overcame Ivo Karlovic's powerful serve to reach the Queen's Club semifinals with a 6-7 (5), 7-6 (5), 7-6 (4) win on Friday. Rafa will next play defending champion Andy Roddick of the U.S., who got a walkover in the quarter-finals when Andy Murray of Britain withdrew after injuring his right thumb in the previous round.

Rafal had just two break points - while not conceding any - which were saved by Karlovic at 3-3 in the first set and 2-2 in the third. "It was a very tough match," Rafa said. "It's a very important win because I beat a specialist on this surface, a big server. I think I returned well, but I didn't have lot of chances."

A double-fault by Rafa in the first tiebreaker was all Karlovic needed, as he closed out the set with his 15th ace but Rafa bounced back to win the second, and Karlovic then netted a backhand volley in the third tiebreaker to give the French Open champion a decisive 5-3 lead. "On grass, especially these matches, everything is decided in two balls," Rafa said. "So it is very important to be prepared, and have the best concentration."