The South African National Road Champion, who rides for UCI pro team Mitchelton-SCOTT, remained largely unnoticed as the bunch charged for the line but timed his sprint to perfection to claim victory in Saint-Just-Saint-Rambert, France.

The 33-year-old, who has been struggling for form since his victory at the Tour Down Under in January, says the stage win was as much of a surprise to him as it was to others.

"When I saw 200 (meters) I thought it's a long way but I have got to give it everything I can and I had surprisingly good legs."

"Since the start of the year, I have had a bit of criticism from other people saying that I have done nothing since the start of the year so to get a big win is something nice," Impey said.

Tuesday's 2nd stage is a 181km rolling run from Montbrison to Belleville, includes four category 3 climbs and one category 4, but may also finish in a bunch sprint.