Spain's Rafael Nadal advanced to the semifinals of the Sony Open Tennis with a 4-6, 6-2, 6-4 victory here over Canadian Milos Raonic, whose huge first serve put a scare into the world No. 1.

Nadal came into Thursday night's match not having lost his serve in three matches but he gifted away a service game late in first set with double faults, leaving himself little margin for error the rest of the way against his powerful opponent.

The Spaniard, however, stuck to his strategy of making a high percentage of first serves and being aggressive from the baseline to test the big Canadian's agility and not allow him time to blast his erratic but dangerous forehand.

The reward was immediate as Nadal raced off to a 4-0 lead in the second set thanks to numerous Raonic forehand unforced errors.

The world No. 12 began controlling his service games again, however, and the match was very much in doubt with the Canadian serving at 3-3 in the third set.

In that game, Raonic exhibited the struggles he faces against the top players when his serve, which at times topped the 140 mph-mark, does not give him a big advantage in the point.

Nadal was able to get the Canadian into some rallies and secured the much-coveted break of serve.

The Spaniard faced a 15-30 situation in the next game after missing a pair of forehands, but he calmly righted the ship to take a 5-3 lead and then served the match out two games later.

"For me to be in semi-finals after losing early in Indian Wells (another big hard-court event earlier this month) is very important for my confidence," Nadal, who has fully recovered from a back injury sustained earlier this year, was quoted as saying on the ATP World Tour's Web site.

"The difference between quarterfinals and semifinals is a lot, and tomorrow I have another day to try to keep playing better."

Next up for the world No. 1 in Friday's semifinals will be another big-hitting player, Czech Tomas Berdyzh, who defeated Ukraine's Alexandr Dolgopolov 6-4, 7-6 (7-3) earlier Thursday.

Nadal, who is seeking his first title in Miami, has dominated his head-to-head against Berdych, leading 17 matches to three.

In women's semifinal action on Thursday, world No. 1 Serena Williams cruised to a 6-4, 6-3 victory over Maria Sharapova and will square off in Saturday's final against China's Li Na, a 7-5, 2-6, 6-3 winner against Slovakia's Dominika Cibulkova.

The Sony Open Tennis tournament is one of the biggest hard-court events on the ATP and WTA calendars. EFE