Golden hour for Di Luca

The 30-year-old Italian beat young Slovenian Janez Brajkovic to the line after a 178km trek which crossed three major climbs before the final ascent to the ski station at Covatilla.

General classification favourites Carlos Sastre and Alejandro Valverde finished together in fifth and sixth place, 22 seconds behind, but the 18km special category climb in the Sierra de Béjar took its toll with last year's winner Denis Menchov, Tour de France champion-elect Oscar Pereiro plus Alexandre Vinokourov and Iban Mayo all losing large chunks of time.

A group of 16 riders broke away early on the first climb of the day, the first category Puerto de Piornal, but their advantage never went beyond four minutes as Sastre's CSC team and Valverde's Caisse d'Epargne squad kept a close eye on proceedings.

Michael Rasmussen, King of the Mountains at the Tour de France, caused the lead group to halve on the second category climb at Lagunilla with 42km to go but the peloton was ominously poised as they began the climb to Covatilla.

Three of the escapees, Inigo Landaluze, Sergio Paulinho and David Arroyo led, and then were in turn dropped, over the first half of the climb as the CSC driven peloton caused many of the highly fancied riders to lose contact with over 5km left.

Jose Angel Gomez Marchante sprung clear but Di Luca, who won two stages in last year's Giro, maintained a fierce tempo behind eventually attacking the elite group with 3km remaining.

22-year-old Brajkovic stayed with him but had no answer over the final 200m as Di Luca sprinted ahead to take a four second lead over the Slovenian on the overall standings.

Andrey Kasheckin burst away from the big name Spaniards to take third spot and he is just 18 seconds behind Di Luca on GC with Sastre a further 11 seconds back and Valverde trailing the leader by 36 seconds.

But it was a sorry day for Mayo who finished 1:44 back, Vinokourov who was at 2:13, Menchov (3:37) whose hopes of retaining his crown now look very slim and Pereiro who lost over five and a half minutes.