Gasquet, who lost the 2007 final to Novak Djokovic on his last visit to Estoril, beat the lowest-ranked player remaining in the field in number 148 de la Nava.

He now faces another Spaniard, Albert Ramos, the fourth seed who saw off local favorite Joao Sousa 6-2, 6-3.

The second semi-final will be decided at the end of ongoing matches between Swiss third seed Stanislas Wawrinka and Dutchman Robin Haase and two-time champion Albert Montanes of Spain, seeded seventh, and holder Juan Martin del Potro.

Gasquet, competing in his fifth ATP quarterfinal of 2012, broke three times in a battle lasting just shy of two hours.

Unheralded fourth seed Ramos meanwhile made it a disappointing afternoon on clay for the local fans as he eliminated the 140th-ranked Sousa in 87 minutes with four breaks of serve and the same number of double-faults from the loser.

Ramos got to the final in Casablanca last month and has now won his 13th match of the year on clay.

Del Potro is competing on clay for the first time on the ATP this season, though he did win a pair of Davis Cup rubbers last month in Argentina's win over Croatia in Buenos Aires.

Wawrinka stands 3-0 over Haase in their series as the Swiss looks for a first clay trophy since Casablanca two years ago.

In the Saturday women's final, Kaia Kanepi of Estonia, the sixth seed, will take on Spaniard Carla Suarez Navarro.

Both of the winners knocked out Italian competition, with Kanepi upsetting top seed Roberta Vinci 6-2, 7-5 and Suarez Navarro ousting Karin Knapp 6-4, 6-0.

Meanwhile, Britain's world No. 4 Andy Murray has pulled out of the Madrid Open with a back injury, organizers said yesterday.

A winner of the tournament in 2008 when it was played indoors on a hard court, Murray reached the quarter-finals in 2009 and 2010 on clay court, and was knocked out in the third round last year.

"It is with regret that on doctors' advice I have to withdraw with injury," the 24-year-old said in a statement.

"I always love coming to Madrid so it is a big disappointment. I look forward to returning next year and wish everyone a great week of tennis." The Scot, whose last match was a quarter-final loss a week ago on clay in Barcelona to Canadian Milos Raonic, informed officials of his situation a day before the men's draw.

This season has seen Murray play in just two clay-court tournaments, also reaching the quarterfinals in Monte Carlo.

Murray's quest to try and close a points gap on Roger Federer will fall by the wayside as he sits out the penultimate major prior to the May 27 start of the French Open.

Murray will need to race for fitness if he is to play in Rome, which starts a week from Monday.

The Madrid tournament was also hit Thursday by the withdrawal of US duo Mardy Fish and Andy Roddick, although the world's top three ranked players — Novak Djokovic, Rafael Nadal and Roger Federer — will be in the Spanish capital.