Bradley Wiggins acknowledged his hopes of winning the Tour of Britain were dashed after losing time to Michal Kwiatkowski on Wednesday.
Kwiatkowski stormed past Albert Timmer (Giant-Shimano), Dylan Teuns (BMC Racing Team) and Jack Bauer (Garmin-Sharp) in the last 400 metres to win the 184.6-kilometre stage from Worcester to Bristol.
The Polish rider now holds the race lead, three seconds ahead of Edoardo Zardini (Bardiani).
Defending champion Wiggins (Team Sky) could only finish 34th " six seconds off the pace.
As a result, he has dropped to sixth " 27 seconds behind Kwiatkowski " and does not think he can win the race anymore with four days remaining.
"I'm still up there but on paper first place has gone now," Wiggins said.
"I can't see myself getting 27 seconds on Kwiatkowski, but the podium is only 12 seconds away.
"He only has to have a puncture in the time trial.
"I wouldn't say the GC [general classification] is over because finishing up there as the defending champion is important."
The riders will race from Exmouth to Exeter over 177.3km in Thursday's stage five.