GENEVA, Switzerland (AFP) - Top seed Stan Wawrinka continued to fine-tune his French Open preparations with a three-set win over Czech Lukas Rosol to make the last-eight in Geneva on Wednesday.

The Swiss beat Rosol 6-4, 3-6, 6-3 in 96 minutes, firing six aces on his way to a quarter-final clash against Argentina's Federico Delbonis who beat Andrey Kuznetsov 6-3, 6-4.

"I'm very happy about this victory," said Wawrinka, who knocked Rafael Nadal out of the Italian Open in Rome last week before going on to the semi-finals.

"I played well today, I'm feeling well. I was a bit less intense during the second set which makes a big difference against players like him. But overall it was a good match."