Belgian rider Philippe Gilbert clinched his second stage win of the Tour of Spain Friday with a final surge while Spain's Alberto Contador held on to the overall leader's red jersey.

Gilbert launched an attack less than a kilometre from the line of the 19th stage and broke ahead of a pack of around 40 cyclists to finish ahead of Spaniards Alejandro Valverde and Daniel Moreno.

The BMC rider, who also won the ninth stage, completed the 178km 19th stage through completely flat terrain from Penafiel to La Lastrilla in four hours 56 minutes and 25 seconds.

"It is my second stage win, I am very happy, my team was attentive all day," said Gilber at the end of the race.

"We discussed the stage and we were told that the end was very technical, it is really where the pack broke up and I thought for me it was better to sprint."

Contador, back in the saddle after a two-year doping ban, finished in 11th place, three seconds behind Gilbert, but he was able to hold on to the overall race lead with just two stages left.

"It was complicated in the end. The last 30 kilometres were very tense," he said.

Valverde, of the Movistar team, is in second place in the overall standings, 1min 35sec behind Contador, while compatriot Joaquim Rodriguez of Katusha is third, 2min 21sec from the leader.

"I fought to win the stage, but Gilbert attacked from far away and it was impossible. Tomorrow is going to be hard," said Valverde.

The Tour continues on Saturday with a mountainous ride from La Faisanera to Bola del Mundo, a distance of 170km that includes several first category climbs.

Rodriguez all but conceded defeat to Contador in the pursuit of victory on Sunday.

"It will be really complicated to take the overall lead, unless a disaster hits Alberto. But I don't think so," said Rodriguez who has held the overall leader's red jersey for much of the race this year.

The 33-year-old had entertained great hopes of making up for his heartbreak in this year's Tour of Italy when he led going into the final stage only to finish second overall after Canadian Ryder Hesjedal overhauled his advantage in the time-trial.

The 21-stage race - one of cycling's three 'major tours' along with the Tour de France and the Giro d'Italia - ends in Madrid on Sunday after covering a total distance of 3,300 kilometres.