Paul-Henri Mathieu sent top seed Croatia's Ivan Ljubicic crashing out of the Open de Moselle to book his place in the semi-finals in Metz.
The Frenchman, who only returned to court in July after a long-term wrist injury, beat Ljubicic 7-6 6-4.
Richard Gasquet came out on top in the battle of the French teenagers as he beat rookie Gael Monfils 7-5 6-1.
Monfils was competing in his first ATP Tour event but could not match the experienced Gasquet, who faces Mathieu.
"He played really well in the first set but I changed my strategy in the second," said the 18-year-old Gasquet.
Monfils, 356th in the world, will not be too disappointed with his Tour debut however as he saw off Belgian Xavier Malisse in the first round.