Australian Orica-GreenEdge rider Leigh Howard seized back the leader's gold jersey in the Tour of Britain as Team Sky's Mark Cavendish slipped back badly in Thursday's fifth stage, which was won by Marc de Maar.
UnitedHealthcare's de Maar, of the Netherlands, made a break for the front with six kilometres of the 147km ride around Stoke-on-Trent remaining, making the move only four kilometres after crashing to the floor.
He crossed the finishing line alone, with Sep Vanmarcke of Garmin-Sharp winning a sprint finish for second place some 15 seconds further down the road.
Cavendish fell away from the leading pack in the hills, and could not stay close enough to retain his overall lead.
The Manxman drops all the way down to 35th in the general classification, with Howard now seven seconds ahead of Dutchman Boy van Poppel atop the standings.
"I rode an aggressive race, I had some attacks myself and luckily I had good legs and could stay with those at the front," Howard told the BBC.
"I'll be having a few problems up the climbs and I can't see myself still in the gold jersey by the end of the week but I'm going to try."
"I knew Cavendish was struggling with the climbs early in the stage, so when the crunch came I knew he wasn't going to go.
"When the break happened, I just made sure I went with them."
Meanwhile a delighted de Maar said: "We were planning for a sprint but there was a bit of movement, I suddenly saw a gap and decided to keep on going.
"I had a rough start to the Tour. I was involved in two crashes and I was thinking about going home.
"I'd come to contend the general classification but lost four minutes in one stage. I lost motivation, but it looks like I have found it again."
The Tour enters Wales on Friday, with a 189.8km sixth stage from Welshpool to Caerphilly.
The eight-stage race finishes in Guildford, Surrey, on Sunday.