First seed Simon converted 6 out of 15 break points and after a slow start he took control of the match, winning in 2 hours and 13 minutes.
Simon’s semifinal opponent will be Matthias Bachinger of Germany, who beat fellow qualifier Daniel Brands 6-4 6-1.
Hungarian qualifier Atilla Balazs is on a good run at this year’s tournament. He booked his place in the semis with a victory over Belgian Xavier Malisse, winning in three sets 4-6 6-3 6-4.
Balazs will play for a final spot against Italy’s Fabio Fognini, who dismissed fellow countryman Andreas Seppi 6-4 6-7 (4) 6-4.