Paul-Henri Mathieu fought back from a set down Monday to upset fourth-seeded Feliciano Lopez 4-6, 7-6 (5), 6-4 in the opening round of the ABN Amro World Tennis Tournament.
Mathieu, ranked 733 in the world after missing the entire 2011 season with a knee injury, looked sharp in beating Lopez in a match that lasted nearly three hours.
''I worked hard during my injury and I think I am fit,'' he said. ''This is a good comeback.''
Another Frenchman, fifth-seeded Richard Gasquet, overcame an injured Flavio Cipolla to win his first-round match 6-3, 1-6, 6-1.
After losing the first set, Cipolla easily took the second, but struggled in the decider with a left thigh injury.