Quesne had two bogeys in his first three holes Friday but the charge down the stretch allowed him to shoot a second-round of 6-under-par 65. He's 9-under 133 for the tournament, one stroke ahead of Danny Willett, who had a second consecutive 67 Friday.
Paul Lawrie shot 66 Friday and is alone in third, two strokes behind Quesne.
A handful of golfers were still on the course when play was suspended because of poor visibility.
First-round leader Gregory Bourdy had four straight bogeys en route to a 4-over 75 and is 4-under for the tournament.
Quesne was inconsistent in his first nine -- the back nine of the Crans-sur-Sierre course -- putting up three bogeys, two birdies and an eagle. The eagle came at the par-5 15th, a hole he had a double bogey on Thursday.
He posted a birdie at the second hole and had birdies on Nos. 6-9 to close the round.