Roger Federer came closer to an elusive French Open title on Wednesday, advancing to his 20th straight Grand Slam tennis semifinal after a straight-set win over home boy Gael Monfils. The Swiss samshed France's last hope with a 7-6 (8-6), 6-2, 6-4 victory and set up a meeting with No. 5 seed Juan Martin Del Potro of Argentina, who beat Spain's Tommy Robredo 6-3, 6-4, 6-2.

The exit of four-time winner Rafael Nadal, who beat Federer in the final the past three years, cleared the way for the Swiss to crown at Roland Garros for the first time.

Only two matches away from completing a sweep of the four major titles, the world number two felt the tension.

Gael Monfils of France plays a shot during his quarter-final match against Roger Federer of Switzerland at the French Open tennis tournament at Roland Garros in Paris June 3, 2009.

"It's also one of the reasons why I was nervous going into this match," he said. "Obviously they also play with my mind, even though it doesn't affect me yet. Now it does."

Victory this time would also move the No. 2 seed into a tie with Pete Sampras's mark of 14 Grand Slam men's singles titles.

Second-seeded Serena Williams, who had been the last former champion left standing in Paris, bitterly lost to Svetlana Kuznetsova 7-6 (3), 5-7, 7-5 despite a courageous fightback.

The 27-year-old, champion of US and Australian Open, rallied from one set and 4-1 down to extend the match to the third set, in which she saved two match points while trailing 5-4 only to see the Russian No. 7 seed celebrate a sensational victory on her third match point.

The American wasted a break point while leading 6-5 in the first set to gift Kuznetsova a tiebreak in which the Russian finally won 7-3.

"It was definitely close. I had chances to win. Just thinking about things that I could have done better." Williams said.

"I made it hard for myself a lot, more than anything. I felt like, I had a chance to do a little bit better, and I didn't." she added.

Kuznetsova, the second-highest ranked player remaining in the women's singles at No. 7, will next play Australia's Samantha Stosur, who beat 19-year-old Romanian Sorana Cirstea 6-1, 6-3.

No. 30 seed Stosur, playing her first-ever Grand Slam singles quarterfinal, held her nerves to put down a late fightback from Cirstea before ending the run of the unseeded dark horse.

Parisian-born Monfils, seeded 11th, traded blows with Federer during a hotly contested first set in which he wasted a set point at 6-5 in the tie-break. It was the Swiss maestro who showed all his years of big point experience, while leading 7-6, to conclude the set with a crisp volley.

The tie was basically ended as a contest after the first set. Although Monfils summoned up all his reserves of courage for a final fling in the third and saved a break point at 4-4, Federer was not to be denied, breaking and holding to love to put an emphatic exclamation mark on a very solid performance.

Roger Federer came closer to an elusive French Open title on Wednesday, advancing to his 20th straight Grand Slam tennis semifinal after a straight-set win over home boy Gael Monfils. The Swiss samshed France's last hope with a 7-6 (8-6), 6-2, 6-4 victory and set up a meeting with No. 5 seed Juan Martin Del Potro of Argentina, who beat Spain's Tommy Robredo 6-3, 6-4, 6-2.

The exit of four-time winner Rafael Nadal, who beat Federer in the final the past three years, cleared the way for the Swiss to crown at Roland Garros for the first time.

Only two matches away from completing a sweep of the four major titles, the world number two felt the tension.

Gael Monfils of France plays a shot during his quarter-final match against Roger Federer of Switzerland at the French Open tennis tournament at Roland Garros in Paris June 3, 2009.

"It's also one of the reasons why I was nervous going into this match," he said. "Obviously they also play with my mind, even though it doesn't affect me yet. Now it does."

Victory this time would also move the No. 2 seed into a tie with Pete Sampras's mark of 14 Grand Slam men's singles titles.

Second-seeded Serena Williams, who had been the last former champion left standing in Paris, bitterly lost to Svetlana Kuznetsova 7-6 (3), 5-7, 7-5 despite a courageous fightback.

The 27-year-old, champion of US and Australian Open, rallied from one set and 4-1 down to extend the match to the third set, in which she saved two match points while trailing 5-4 only to see the Russian No. 7 seed celebrate a sensational victory on her third match point.

The American wasted a break point while leading 6-5 in the first set to gift Kuznetsova a tiebreak in which the Russian finally won 7-3.

"It was definitely close. I had chances to win. Just thinking about things that I could have done better." Williams said.

"I made it hard for myself a lot, more than anything. I felt like, I had a chance to do a little bit better, and I didn't." she added.

Kuznetsova, the second-highest ranked player remaining in the women's singles at No. 7, will next play Australia's Samantha Stosur, who beat 19-year-old Romanian Sorana Cirstea 6-1, 6-3.

No. 30 seed Stosur, playing her first-ever Grand Slam singles quarterfinal, held her nerves to put down a late fightback from Cirstea before ending the run of the unseeded dark horse.

Parisian-born Monfils, seeded 11th, traded blows with Federer during a hotly contested first set in which he wasted a set point at 6-5 in the tie-break. It was the Swiss maestro who showed all his years of big point experience, while leading 7-6, to conclude the set with a crisp volley.

The tie was basically ended as a contest after the first set. Although Monfils summoned up all his reserves of courage for a final fling in the third and saved a break point at 4-4, Federer was not to be denied, breaking and holding to love to put an emphatic exclamation mark on a very solid performance.