Peter Kennaugh led home a strong showing on from Team Sky on stage four of the Tour de Pologne as the battle for overall honours began in Cieszyn.
The Brit was active in a tough finale and was in a strong position and he rounded the tight right hander onto the cobbled final climb.
The young Brit crossed the line in 11th place after a day of climbing, the first of four Team Sky riders to make the all-important juncture into the front group as the peloton fractured on the final lap of the 6.3km finishing circuit.
Steve Cummings continued his return to form with 13th, joining Kennaugh three seconds back on the stage winner, while Morris Possoni and Lars-Petter Nordhaug were just seven seconds further behind to cap off a strong team performance.
At the finish it was Peter Sagan who put in a devastating attack on the final climb to take a comfortable victory and move into the race lead.
The Liquigas rider accelerated away from his rivals with 500 metres to go on the tough cobbled ascent and opened up a clear gap of three seconds on the line to take his ninth win of the season.
Last year’s race winner Dan Martin (Garmin-Cervelo) was second across the stripe while Marco Marcato (Vacansoleil) rounded out the podium places as a select group contested the finish.
The stage marked a new phase in the race as the undulations began after three sprint stages, with forest-lined climbs and picturesque scenery replacing nervous city-centre circuits.
A tough stage was always in store as the riders took on the 177km route from Oświęcim to Cieszyn and a four man break wasted little time in moving clear after 30km.
Quick Step and Liquigas were on duty controlling the tempo on the front as the peloton made three ascents of the Kubalonka climb on a scenic but punishing circuit.
The final time over the climb it was Chad Beyer (BMC) who made a break for it in a move that saw the remainder of the escapees swept up while the American pressed on.
Alexandre Pliuschin (Katusha) bridged across to the BMC man and was the first rider to enter the finishing circuit, yet it would be Simon Clarke (Astana) who took up the baton only to be caught as he took the bell for the final lap.
It was here that Vincenzo Nibali attacked as Liquigas wound up the pace, splitting the peloton to pieces and setting up Sagan for a victory he made look easy.
After keeping out of trouble on the first three days of the race Sports Director Sean Yates was happy to see the team now influencing the race from the sharp end.
He said: "It was a difference race today. Lots of action and a tough finishing circuit. Completely different scenery and weather. Down here in the south it’s like a different country almost in the mountains.
"Pete had some mechanical issues so he wasn’t able to sprint. Otherwise it might have been possible for a top-5 so it was a bit unfortunate. But otherwise he rode well. He was there with the guys like Nibali when they hit out so he is in good shape and he got himself in that little split which bodes well for the next couple of days.
"Tomorrow could well be similar to today. Try and follow and then pounce if you can in the final. These stages you have to be a bit clever if you want to be a GC contender or win a stage.
"The guys are all motivated. Pete’s in good form and that gives the guys confidence in who they are working for."