Andrew Talansky claimed a landmark victory on stage three at Paris-Nice to move into the yellow jersey.
The young American rode a canny race to infiltrate a decisive winning breakaway, before out-sprinting his rivals to take a first win of the year for his Garmin-Sharp outfit.
A seven-man group had pushed clear on the descent of the final climb into Brioude, with Andriy Grivko (Astana) and Davide Malacarne (Europcar) rounding out the top three across the line.
Team Sky had been active in the closing stages, splitting the bunch on the Cote de Mauvagnat to put overnight leader Elia Viviani (Cannondale) into difficulties.
On soaking-wet roads, an already stretched peloton finally split, with Roman Bardet (AG2R-La Mondiale) pushing on alongside Malacarne, Grivko, Gorka Izagirre (Euskaltel-Euskadi) and Team Sky's David Lopez and Richie Porte.
A tense chase ensued, with a number of big names in the second group digging deep to finish seven seconds back on a thrilling day of racing.
Keen to put time into his general classification rivals, Porte pulled the group into the final 500m, but it was Talansky who had conserved enough energy to win the sprint and bag the time bonuses to carve out a three-second margin over Grivko overall.
Wet conditions greeted the peloton ahead of what looked set to be the toughest stage of the race thus far - a 170.5km run into Brioude.
Four riders headed up the road as the race headed out of Chatel-Guyon - Sebastien Minard (AG2R-La Mondiale), Mads Christensen (Team Saxo-Tinkoff), Marijn Keizer (Vacansoleil-DCM) and neo-pro Alexis Vuillermoz (Sojasun) - building out a gap of just over four minutes.
In behind it was Cannondale who led the chase on behalf of overnight leader Viviani, wit the gap holding firm over the day's pair of third category climbs. As the day wore on, Omega Pharma - Quick-Step again lent their weight to the chase.
Yet it wasn't until the final 25km when the race really burst into life, with Team Sky setting a stinging tempo to split things apart and set up a thrilling finish.
Stage three result
1 Andrew Talansky (USA) Garmin-Sharp, 4:06.15
2 Davide Malacarne (Ita) Europcar, same time
3 Gorka Izaguirre (Spa) Euskaltel-Euskadi, st
4 David Lopez (Spa) Team Sky, st
5 Richie Porte (Aus) Team Sky, st
6 Romain Bardet (Fra) Ag2r-La Mondiale, st
7 Andriy Grivko (Ukr) Astana, st
8 Jonathan Hivert (Fra) Sojasun, +7secs
9 Enrico Gasparotto (Ita) Astana, st
10 Maxime Bouet (Fra) Ag2r-La Mondiale
1 Andrew Talansky (USA) Garmin-Sharp, 14:39.36
2 Andriy Grivko (Ukr) Astana, +3secs
3 Davide Malacarne (Ita) Europcar, same time
4 Sylvain Chavanel (Fra) Omega Pharma - Quick-Step, +4
5 Gorka Izaguirre (Spa) Euskaltel-Euskadi, +5
6 Lieuwe Westra (Ned) Vacansoleil-DCM, +6
7 Richie Porte (Aus) Team Sky, +7
8 Peter Velits (Svk) Omega Pharma - Quick-Step, +8
9 David Lopez (Spa) Team Sky, +9
10 Jonathan Hivert (Fra) Sojasun, +12