Thomas, along with Tony Martin and Lars Boom, had opened up a 13-second lead with a little over 5km to go, only for Griepel, assisted by Lotto-Soudal team-mate Greg Henderson, to reel in the leaders and hold off France’s Arnaud Demare.
Thomas is 13 seconds behind the overall leader, Etixx-QuickStep’s Polish rider Michal Kwiatkowski, while former Tour de France champion Sir Bradley Wiggins slipped 42 seconds off the pace after finishing 142nd on the 172km stage.
“Paris-Nice is a big race and it usually has quite a few top sprinters,” said Griepel. “I hadn’t competed in it for several years, so I am delighted.”
Two-time Tour de France winner Alberto Contador, meanwhile, has confirmed he will end his career with Russian team Tinkoff-Sazo after agreeing a one-year contract extension yesterday.