Briton Mark Cavendish won the 12th stage of the Tour of Spain as he amazingly rode unchallenged to the line.

The 172.5km stage was made for a dramatic sprinting finish but Cavendish's main rivals misjudged the course in a gift for the sprinter.

The HTC-Columbia attack came at a time where rivals failed to respond, resulting in him cruising home to victory ahead of Garmin-Transitions' sprinter Tyler Farrar. Cavendish's lead-out man, Matthew Goss, finished third.

"That (victory) was because of my lead-out man," Cavendish said.

"Gossy did an incredible job. It was so chaotic in the final stages and I thought we were too far back with 600 metres go. Then Gossy gave me a lead-out and I saw the gap we had."

"I actually wanted to give him the win but he pulled over. The team worked really well."

It was Cavendish's first stage win on the Tour of Spain which ensured he has now won a stage in cycling's three biggest races with his triumph on stage 12 adding to his victories at the Tour de France and Giro d'Italia.

He rode home in an impressive time of four hours and 30 seconds to record his 21st grand tour stage win.

"I just love winning and being part of a winning team. I hope to carry on winning for as long as I'm professional," a delighted Cavendish said.

The day's stage saw an early break with several riders breaking away after just 10km with Milram's Markus Eichler and Xacobeo Galicia's Gustavo Cesar leading the pack.

The peleton hauled in the breakaway with 23km remaining before Goss' attack led the way for Cavendish's first win at the Tour of Spain.