Mark Cavendish sprinted to victory in a thrilling finish to stage four of the Tour of Britain in Llanberis as Sir Bradley Wiggins retained his overall lead.
Cavendish (Omega Pharma - Quick-Step) jumped into the slipstreams of two rivals before powering to his first victory of this year's race ahead of Elia Viviani (Cannondale) in second and Steele von Hoff (Garmin-Sharp) in third.
The sprint came only after the day's 11-man breakaway had been finally caught 800m from the line following a compelling stage-long duel between themselves and Team Sky on the front of the peloton.
A battle for position ensued as the two groups came together at high pace, but Cavendish was ushered safely through the melee by his team-mates and then followed the wheels of both Sacha Modolo (Bardiani Valvole - CSF Inox) and Matteo Pelucchi (IAM Cycling) before launching a decisive burst for the line.
Wiggins followed safely in the peloton to retain his 37-second lead in the general classification over Team Sky team-mate Ian Stannard, who also finished in the main bunch.
Cavendish said afterwards: "The Bardiani guys went and I jumped on to them. Then Pelucchi from IAM went and I jumped on to him. I was kind of hopping in the last 500m, but without the guys [his team-mates], there would be no way was there. I am really happy."
Stage four took the riders on a 188.4km route from Stoke-on-Trent to Snowdonia containing three climbs in the final 60km.
Eleven riders broke away early and despite none of them being an immediate threat in the general classification, Team Sky made the mistake of allowing Omega Pharma - Quick-Step and Cannondale - both sprint teams - to put men in the escape.
That meant Wiggins's team-mates had to chase the breakaway down entirely on their own and although they eroded the maximum lead of 3min 50sec down to 1min 45sec by 30km to go, they began to run out of steam and it looked like the escapees would stay clear.
However, Stannard, who had been sheltering behind his team-mates, hit the front and took a chunk out of the gap, and then Dan Martin (Garmin-Sharp) attacked on the day's final climb, Pen-y-Pass, which summitted 9km from the finish, to bring it further down to under a minute.
But the Irishman was merely acting as a launchpad for team-mate Jack Bauer, who surged ahead over the top and then opened up a lead on the subsequent descent.
He was soon reeled back in by Team Sky, though, who in the process further reduced the breakaway's lead to just a handful of seconds.
Several of the escapees attempted lone attacks, but with the sprints teams now having taken over on the front of the peloton, their efforts were in vain and Cavendish soon took a decisive control of affairs.
He was joined in the top 10 by three other Britons - Owain Doull, Scott Thwaites and Chris Opie - and an Ireland's Sam Bennett.
Stage four result
1 Mark Cavendish (GB) Omega Pharma - Quick-Step, 4:45:42
2 Elia Viviani (Ita) Cannondale, same time
3 Steele von Hoff (Aus) Garmin-Sharp, st
4 Matteo Pelucchi (Ita) IAM Cycling, st
5 Jose Joaquin Rojas (Spa) Movistar, st
6 Owain Doull (GB) Great Britain, st
7 Evaldas Siskevicius (Ltu) Sojasun, st
8 Scott Thwaites (GB) NetApp-Endura, st
9 Chris Opie (GB) UK Youth, st
10 Sam Bennett (Irl) AN Post-Chain Reaction, st
22 Bradley Wiggins (GB) Team Sky, st
1 Bradley Wiggins (GB) Team Sky, 16:11:36
2 Ian Stannard (GB) Team Sky, +37secs
3 Martin Elmiger (Swi) IAM Cycling, +47
4 Jack Bauer (NZ) Garmin-Sharp, +55
5 Alex Dowsett (GB) Movistar, +57
6 David Lopez (Spa) Team Sky, +1:17
7 Michal Golas (Pol) Omega Pharma - Quick-Step, +1:18
8 Sergio Pardilla (Spa) MTN-Qhubeka, same time
9 Gerald Ciolek (Ger) MTN-Qhubeka, +1:21
10 Alexander Wetterhall (Swe) NetApp-Endura, same time
- Blue and white jersey (points classification): Elia Viviani (Cannondale)
- Green polka dot jersey (mountains classification): Angel Madrazo (Movistar)
- Green and red jersey (intermediate sprints competition): Aaron Gate (An Post - Chainreaction)