France's Nacer Bouhanni moved into the overall lead of Paris-Nice after sprinting to victory on stage one.
The FDJ rider narrowly beat Italian duo Alessandro Petacchi (Lampre-Merida) and Elia Viviani (Cannondale) into second and third respectively after an action-packed final 25km into Nemours.
Bouhanni claimed 10 bonus seconds for his victory and now takes over the yellow jersey from compatriot and prologue winner Damien Gaudin (Europcar), who drops down into second overall on the same time.
Sylvain Chavanel (Omega Pharma - Quick-Step) finished 12th on the stage to make it three Frenchmen in the top three of the general classification, one second back.
Bouhanni, the French national champion, is riding in his first Paris-Nice and now has two victories this season, having won stage six of the Tour of Oman.
He said afterwards: "I am above all delighted for the team as they did a hell of a job. Jeremy Roy did a great job to bridge the gap on the escapees.
"In the finale, I didn't care too much about what was happening behind with [Tom] Boonen or [Marcel] Kittel. I was focused on my sprint.
"I am all the happier as this is my first Paris-Nice and it is extraordinary to win the first stage with the French champion's jersey on. We will keep fighting in the next few stages."
The race's first road stage took the riders on a flat, 195km route from Saint-Germain-en-Laye, just west of Paris, to Nemours, south of the capital.
Romain Sicard (Euskaltel-Euskadi), Bert-Jan Lindeman (Vacansoleil-DCM) and Yannick Talabardon (Sojasun) broke away from the peloton immediately after the gun and quickly opened up a gap that stretched to seven minutes 20 seconds at its peak.
Lindeman won both of the day's intermediate sprints to claim three bonus seconds at each, and also crested the day's only categorised climb, the Cote de Buthiers, first to move into the polka dot jersey.
Sicard ran out of legs with around 35km to go and dropped back into the pack, while Lindeman and Talabardon hung on until just over 22km to go as BMC and Omega Pharma - Quick-Step stepped up the pace on the front of the bunch.
Crosswinds then helped split the peloton into two groups, with Tom Boonen (Omega Pharma - Quick-Step), David Millar (Garmin-Sharp) and Jens Voigt (RadioShack-Leopard) among the big names to be caught out and cut adrift.
But there was more drama to come, when pre-stage favourite Marcel Kittel (Argos-Shimano) suffered a mechanical problem and dropped out of contention and into the second group.
The gap to the chasers stretched to 40 seconds and although that was hauled back to 25 seconds inside the last 10km, it soon became apparent that they would be unable to bridge to lead bunch and they consequently sat up.
Up ahead, Petacchi launched his sprint first, but Bouhanni was strong enough to round the veteran Italian and win by half a wheel, with the surging Viviani narrowly claiming third ahead of Lotto-Belisol's Jens Debusschere.
Stage one result
1 Nacer Bouhanni (Fra) FDJ, 4:47.24
2 Alessandro Petacchi (Ita) Lampre-Merida, same time
3 Elia Viviani (Ita) Cannondale, st
4 Jens Debusschere (Bel) Lotto-Belisol, st
5 Heinrich Haussler (Aus) IAM Cycling, st
6 Mark Renshaw (Aus) Blanco, st
7 Jose Joaquin Rojas (Spa) Movistar, st
8 Leigh Howard (Aus) Orica-GreenEDGE, st
9 Borut Bozic (Slo) Astana, st
10 Romain Feillu (Fra) Vacansoleil-DCM
1 Nacer Bouhanni (Fra) FDJ, 4:51.01
2 Damien Gaudin (Fra) Europcar, same time
3 Sylvain Chavanel (Fra) Omega Pharma - Quick-Step, +1sec
4 Lieuwe Westra (Ned) Vacansoleil-DCM, st
5 Elia Viviani (Ita) Cannondale, st
6 Alessandro Petacchi (Ita) Lampre-Merida, +2
7 Wilco Kelderman (Ned) Blanco, st
8 Geoffrey Soupe (Fra) FDJ, st
9 Peter Velits (Svk) Omega Pharma - Quick-Step, +3
10 Tony Gallopin (Fra) RadioShack-Leopard, st