The Frenchman broke once in each set to reach his best career semifinal.
The No. 3 seed rolled over the German, 6-3, 6-0.
The 30-year-old Frenchman has now won seven of 10 matches against the Top 20 after outdueling Auger-Aliassime Friday.
Some results have been hidden because they may be inaccessible to you
Show inaccessible results