Italian Rinaldo Nocentini of AG2R retains the race leader's yellow jersey after 12 of the 21 stages with a 6sec and 8sec lead respectively on race favourites Alberto Contador and Lance Armstrong of Astana.

But ahead of likely hostilities in the yellow jersey battle on the hilly 13th stage, Soerensen provided some welcome drama after it became clear the sprinters' teams were not interested in chasing down the break.

Having fought to join a first, six-man breakaway that was allowed to go by the peloton, Soerensen then realised he would have little chance if he got to the finish with some of his companions.

That prompted him to attack twice in the closing stages, a decision that ultimately allowed him to come over the finish line savouring his triumph.

''The worst for me would be to come to the finish having used all my power, and being up against a guy like [Franco] Pellizotti,'' Soerensen said.

''If it came to sprint with the others I knew I wouldn't have had any power left.''

With more than 211.5km of racing over slightly rolling terrain ahead, the attacks came thick and fast in a first hour in which the peloton covered 48km.

While that pace helped force three riders out of the race, none of the attacks was allowed to leave the peloton's clutches until the 64km mark, when a six-man group formed.

Soerensen, , competing in his eighth Tour, then pulled away from the main bunch to join the group and they were finally allowed to go on unhindered for a lead that fluctuated between four and five minutes.

With 23km to race, Soerensen set out his stall by attacking the frontrunners and he was immediately countered by Frenchman Sylvain Calzati of Agritubel.

A desperate pursuit continued behind them, however, and with 10km to go their lead was down to only 13sec. Soon, the second part of Soerensen's plan was put into action.

Just as the five chasers were closing in, the 34-year-old Dane, known for years as a loyal ''domestique'', attacked the fading Calzati, who was swallowed up, and went off on his own to finish 48sec ahead of the bunch.

''Personally I will carry this win with me forever,'' Soerensen said later when asked to describe what his feat meant to him.

''To have won a stage in the Tour, as you know, is an extremely big thing. Usually I don't get many chances to go out on my own, so that makes the victory and the satisfaction even better.'' AFP