Federer, seeded third this week, became the seventh man in the Open Era to win 800 matches when he stopped Juan Monaco 6-3, 7-5. He won the last four games of the first set and used an 11th-game break in the second to set up the win.
He joins Jimmy Connors, Ivan Lendl, Guillermo Vilas, John McEnroe, Andre Agassi and Stefan Edberg as Open Era players with at least 800 match wins. Connors owns the record with 1,242. Federer is 800-186 in his career.
World No. 1 Novak Djokovic dropped out of the Paris Masters before meeting sixth-seeded Jo-Wilfried Tsonga in the quarterfinals. Djokovic cited a right shoulder injury as the reason for withdrawal.
Fifth-seeded Tomas Berdych snapped the 17-match winning streak of Andy Murray, the No. 2 seed, in a tough 4-6, 7-6 (7-5), 6-4 match that took 3 hours, 13 minutes. Berdych fought off six break points in the third set and turned in the only break of the set in the ninth game.
Unseeded John Isner ousted fifth-seeded David Ferrer 6-3, 3-6, 6-3. Isner won 20-of-24 points on serve in the third set and got his second break of the match in the set to advance.
Federer will go against Berdych in Saturday semifinals. Federer owns a 9-4 career series advantage, but Berdych has won three of their last four meetings.
Isner won the only time he was paired against Tsonga.