The top-ranked Swiss was playing the 46th-ranked Paire for the first time.
Federer next faces another Frenchman, Paul-Henri Mathieu, who defeated Grigor Dimitrov of Bulgaria, 7-6 (2), 7-6 (4). The other semifinal pairs the No. 2 and No. 3 seeds, Juan Martin del Potro of Argentina and Richard Gasquet of France.
Del Potro, who won in Vienna last weekend, overcame a one-set deficit and 20 aces by South Africa's Kevin Anderson to win 3-6, 7-6 (3), 6-2.
Gasquet, still hoping to qualify for the season-ending ATP World Tour Finals in London, beat sixth-seeded Mikhail Youzhny of Russia 6-2, 7-6 (5).