Rafael Nadal remains on course for a record seventh French Open title after he dismissed the challenge of fellow Spaniard Nicolas Almagro to notch up his 50th Roland Garros victory.
The world No.2 triumphed 7-6 6-2 6-3 over the 12th seed as he goes in search of the 11th grand slam title in his illustrious career.
Standing between Nadal and a seventh Paris final is another Spaniard, David Ferrer, after the No. 6 seed beat Britain's Andy Murray 6-4 6-7 6-3 6-2.
The former world No. 1 has lost only once at the French Open since making his debut as an 18-year-old in 2005. He is yet to lose a set in this year's tournament.
"It was a tough one, but I am through and I am very happy," Nadal told the ATP Tour's official website. "You cannot expect to win an easy match in the quarterfinals of a grand slam.
On his semi-final against Ferrer, Nadal added: "We played each other a lot of times. His game bothers everybody because he's one of the best players in the world on every surface -- on clay especially.
"He's a complete player. It's very difficult to play against him, because his movement is probably the best in the world and he's able to hit the ball very early a lot of the time."
Should Nadal secure his seventh title he will go one better than legendary Swede Bjorn Borg, who has six. He will also match Bjorg's record of 11 career grand slam titles.
Murray, who said he was satisfied with his performance in the tournament despite going out to a player seeded two places below him, said Nadal is the favorite to win.
He told reporters: "I think the four best clay court players in the world are left in and whoever plays best will win. Probably have to favor Rafa slightly, but everyone is playing very, very well."
Ferrer's victory ensured he made the final four of the French Open for the first time in his career, a surprise statistic for someone who is renowned as a clay court specialist.
He said his four-set win over Murray was grueling, but good preparation for his showdown with Nadal, who he labeled the best player on clay ever.
"Tonight's match was very hard, physically very difficult," he said. "But I am happy to be in the semifinals at Roland Garros for the first time.
"It will be a tough match against Rafa, he's the best in history on this surface, but I hope to have a good match."
Murray's disappointment was evident on court, as he made 59 unforced errors during the match and seemed to be troubled by a series of injuries.
"He had his chances and converted them," he said of Ferrer. "He's solid and consistent and if you don't convert opportunities against him, the games become longer and the pressure builds on you.
"But it was a good tournament for me. I felt better coming in this year than I did last year. I lost to a better clay court player tonight. There are things to work on but I knew it would be a tough match."
Thursday sees the first semifinal, between world No. 1 Novak Djokovic and 16-time grand slam champion Roger Federer, take place.