Edoardo Zardini battled back from a late attack by Nicholas Roche to claim victory on stage three of the Tour of Britain.
The Bardiani-CSF rider had led on the final climb from Newtown to the summit finish atop of the Tumble before Roche (Tinkoff-Saxo) cruised past him, but the Italian surged back to triumph by nine seconds and claim the overall lead.
His advantage over Michal Kwiatkowski (Omega Pharma-Quick Step) stands at 13 seconds after the Pole followed him over the line in second place, with Roche settling for third on the 179.9-kilometre stage.
Dylan Teuns (BMC Racing) and Bradley Wiggins (Team Sky) completed the top five, while yellow jersey wearer Mark Renshaw (Omega Pharma-Quick Step) was well down on a tough day that included four category climbs.
Tinkoff-Saxo rider Manuele Boaro took maximum points in the opening three climbs and was joined in the opening breakaway group by five other riders, including king of the mountains leader Mark McNally.
Following the three intermediate sprints, which saw Sonny Colbrelli (Bardiani-CSF) hold onto his green jersey, three riders moved clear of the breakaway group, while Mark Cavendish led the peloton for Omega Pharma-Quick Step.
Slowly the Manx rider began to reel in the leaders but Boaro proved a tough nut to crack and pushed out on his own inside the final 10 kilometres.
Eventually the Italian was absorbed into the peloton and that was Zardini's cue.
With Jack Bauer (Giant-Shimano) for company, the 24-year-old pushed ahead and as the incline increased it was the Bardiani rider who struck out on his own.
However, his chance looked to be over when Roche turned a big gear to fly past him in the closing stages.
Zardini refused to be beaten, though, and immediately came back at the Irishman before sprinting for the line and seizing the yellow jersey.