Cavendish leads the Tour's points competition
Tour of Spain points leader Mark Cavendish kept up his fine run of form as he secured his third stage win with victory in Thursday's 18th stage.
Cavendish was first over the line in a bunch sprint, edging Argentina's Juan Jose Haedo into second place, with Manuel Antonio Cardoso in third.
Italy's Vincenzo Nibali retains the overall lead in the Tour.
He is 38 seconds ahead of Ezequiel Mosquera going into Friday's 231.2km stage, the longest of the Tour.
Cavendish's third stage win in Spain goes alongside the 15 he has recorded in the Tour de France over the past three years, and five over two years in the Giro d'Italia.
He is the first British rider to win three Vuelta stages in one edition and needs just one more to equal Michael Wright as the most successful British rider in the Vuelta.
The 25-year-old from the Isle of Man also won the leader's red jersey in Spain after winning the opening stage, but insisted his success was down to the team spirit in his HTC-Columbia team.
"It's me that crosses the line first but it's the guys who put me there," he said on Thursday, referring to his team-mates.
He admitted to "panicking a bit" when he fell off the pace with four kilometres to go, but said team-mate Peter Velits had pulled him back into contention.
"There was a moment when I suddenly lost 50 or 60 places and I panicked," Cavendish said.
"I shouted across to Peter and he did a massive turn of about a kilometre or so, guiding me up the side of the bunch back to where I needed to be.
"He's fighting for the overall victory but he was still prepared to use up a lot of energy for me. That shows real commitment to the team and it takes a very special person to do that. I can't thank him enough."
Saturday's mountainous penultimate stage, which ends on the summit of the Bola del Mundo in the Guadarrama mountains northwest of Madrid, is widely expected to prove decisive in the race for the overall Tour victory.
"Mosquera and I will fight it out for the Tour in the Bola del Mundo," said Tour leader Nibali.
"I suppose that others will attack me but he's the most dangerous."