Italy's Edoardo Zardini timed his late break to perfection to win a summit finish at the end of the 179.9km third stage of the Tour of Britain in Wales.
Zardini pulled clear as the peloton tackled the ascent of The Tumble on the outskirts of Abergavenny to win by nine seconds from Michal Kwiatkowski.
The Bardiani-CSF rider's victory takes him top of the general classification, 13 seconds clear of Kwiatkowski.
Defending champion Bradley Wiggins came home in fifth place, 14 seconds down.
The Team Sky rider is 24 seconds adrift of Zardini in the overall standings with five stages remaining.
Ireland's Nicolas Roche (Tinkoff-Saxo) finished third on the stage out of Newtown and is also third in the GC, four seconds behind Polish Omega Pharma - Quick-Step rider Kwiatkowski.
Roche briefly moved ahead of Zardini as the pair battled at the front on the final climb but the Irishman had no response when the 24-year-old Italian kicked again to win in a time of 4 hours 35 minutes 2 seconds.
|What will happen on stage four?|
|"It is another tough start and there will be some tired legs in the peloton after Tuesday's stage in Wales. I'm expecting another strong breakaway to form. There is a tricky-looking ramp close to the finish in Bristol which could be a great launch pad for any rider chasing the overall race victory, who is looking to make up any time they have lost on the previous stages." Read Ben Swift's guide to all nine stages|
"It's a fantastic day for me and the team," Zardini told Eurosport. "I attacked at the bottom of the climb and finished strong at the end.
"The Tour of Britain has started in the best way. This is the most important result of my career. I am really happy."
Stage 3 result:
1. Edoardo Zardini (Ita/Bardiani)4hrs 35mins 02secs
2. Michal Kwiatkowski (Pol/Omega Pharma - Quick-Step) +9secs
3. Nicolas Roche (Irl/Tinkoff-Saxo) +11secs
4. Dylan Teuns (Bel/BMC)
5. Bradley Wiggins (GB/Team Sky) +14secs
6. Giovanni Visconti (Ita/Movistar)
7. David Lopez Garcia (Spa/Team Sky)
8. Sebastian Reichenbach (Swi/IAM) +16secs
9. Jon Izaguirre Insausti (Spa/Movistar)
10. Leopold Konig (Cze/NetApp-Endura)
Overall classification after stage 3:
1. Edoardo Zardini (Ita/Bardiani)11hrs 30mins 21secs
2. Michal Kwiatkowski (Pol/Omega Pharma - Quick-Step) +13secs
3. Nicolas Roche (Irl/Tinkoff-Saxo) +17secs
4. Dylan Teuns (Bel/BMC) +21secs
5. Bradley Wiggins (GB/Team Sky) +24secs
6. David Lopez Garcia (Spa/Team Sky)
7. Jon Izaguirre Insausti (Spa/Movistar) +26secs
8. Leopold Konig (Cze/NetApp-Endura)
9. Sebastian Reichenbach (Swi/IAM)
10. Giovanni Visconti (Ita/Movistar) +37secs