Gianni Meersman of the Lotto-Belisol team claimed victory in the fourth stage of Paris-Nice, with Bradley Wiggins holding on to the leader's yellow jersey.
Meersman crossed the finish line in Rodez ahead of Grega Bole (Lampre-ISD), who had launched the final sprint, and Dutchman Lieuwe Westra (Vacansoleil-DCM)
Wiggins (Sky) kept main rival Alejandro Valverde (Movistar) in his sights in the final climb.
The Spaniard finished in eighth position, two places ahead of Wiggins, but the 20sec time difference between the two men remained unchanged.
See full standings, stages and teams at our Paris Nice Mini Site.
"Our objective today was to let a breakaway get away until the end," said Wiggins. "But Rabobank went for it, because the gap was three minutes.
"It was perfect for us. We stayed on their wheels and we were able to rest the guys in the team for the next stages.
"The final was crazy -- there were roundabouts, it was really dangerous, but I was OK and I stayed in the top five the whole time."
Simon Gerrans was a casualty of the messy finale, crashing with six kilometres left after a teammate fell taking a bend too quickly, bringing Gerrans down with him. Both riders got back up and continued but Gerrans was unable to return to the finishing group.
Having finished third in the previous stage, 26-year-old Meersman registered his second success of the season after winning a stage in the Volta ao Algarve in Portugal earlier this year.
"First place is what counts," said Meersman, who was plagued by injuries between 2007 and 2009.
"Yesterday (Tuesday), everyone said it was good when I finished third, but what matters is being able to lift your arms.
"You don't make sacrifices to finish second or third. This winter I've trained a lot for the sprints. I have to thank the team, who worked really hard."
Five riders forged ahead after 18 kilometres on the undulating 178-kilometre stage, which featured two category 2 climbs and consecutive category 3 ascents up Cote d'Aubert le Cres and the short but steep Cote de Bourran up to Rodez.
Spaniard Luis Angel Mate Mardones (Cofidis), Belgian Bart De Clercq (Lotto-Belisol), Australian Leigh Howard (GreenEDGE) and French pair Pierrick Fedrigo (FDJ) and Jean-Christophe Peraud (Ag2r) opened up an early lead of five minutes on the main bunch.
But the five-man breakaway's lead was trimmed to 1 minute and 30 seconds with 40 kilometres left, and less than a minute heading into the last two climbs.
On the penultimate climb, Cote d’Aubret Le Cres, polka-dot jersey holder Thomas De Gendt (Vacansoleil-DCM) attacked on his own. The Belgian was caught with seven kilometers to go just as Gerrans crashed.
Valverde’s Movistar team then took control, hoping for a repeat of yesterday’s stage win in Lac de Vassiviere. Joaquin Rojas led the way for the green jersey holder, with Wiggins on their heels.
On the last climb, two kilometers from the line, Andreas Kloeden (RdioShack-Nissan) tried his luck but was caught with 500 metres to go when Bole launched the sprint. The Slovenian did not have any gear left when Meersman passed him on the line for victory.
Illness took its toll on the peloton with five riders missing the start. Joost Posthuma and Jan Bakelants (both RadioShack),Taylor Phinney (BMC), Olivier Kaisen and Adam Hansen (both Lotto-Belisol), suffering from stomach bugs or bronchitis.
Thursday's fifth stage takes the peloton on a spectacular 178.5km ride to Mende, which culminates in a 3km climb.
Stage 4: 183km, Brive-la-Gaillarde to Rodez.
1 Gianni Meersman (Bel) Lotto-Belisol 4:21:01
2 Grega Bole (Slo) Lampre-ISD
3 Lieuwe Westra (Ned) Vacansoleil-DCM
4 Xavier Florencio Cabre (Spa) Katusha
5 Jonathan Hivert (Fra) Saur-Sojasun
6 Simon Geschke (Ger) Project 1T4i
7 Nicolas Roche (Irl) Ag2R
8 Alejandro Valverde (Spa) Movistar
9 Francesco Gavazzi (Ita) Astana
10 Bradley Wiggins (GBr) Sky
1 Bradley Wiggins (GBr) Sky 13:30:52
2 Levi Leipheimer (USA) Omega Pharma-Quick Step 0:00:06
3 Tejay Van Garderen (USA) BMC 0:00:11
4 Sylvain Chavanel (Fra) Omega Pharma-Quick Step 0:00:14
5 Maxime Monfort (Bel) RadioShack-Nissan 0:00:18
6 Lieuwe Westra (Ned) Vacansoleil-DCM
7 Alejandro Valverde (Spa) Movistar 0:00:20
8 Jose Joaquin Rojas (Spa) Movistar 0:00:29
9 Simon Spilak (Slo) Katusha 0:00:33
10 Robert Kiserlovski (Cro) Astana 0:00:36