Italian Angelo Furlan has won his second stage of the Tour of Spain, edging a bunch sprint at the Warner Brothers Park near Madrid.

The Alessio rider clocked a time of three hours and 18 seconds to win the 141.2-km 20th stage ahead of compatriot Alessandro Petacchi and German Erik Zabel.

It was Furlan's second sprint victory of the week after winning in Salamanca.

US Postal rider Roberto Heras clung on to his overall lead, but with Sunday's time trial remaining his one minute and eight second advantage is precarious.

Second-placed Aitor Gonzalez did not eat into the lead, but his sprinting prowess may count on the final 41.2-km stage, which ends at Real Madrid's Santiago Bernabeu stadium.

But Heras, who is aiming to clinch his second Vuelta victory in three years, says he is unworried.

"I am not worried because it's too easy for your legs to block if you panic.

"However, it's true that Gonzalez showed in the Tour of Italy that he knows how to keep something back for the final part of a three-week race.

"Tomorrow, the first part will be decisive, because that is where you establish the important time differences."

Gonzalez, meanwhile, is hoping that history repeats itself.

Last year, time triallist Angel Casero overhauled climber Oscar Sevilla to take overall victory on the last day's racing.

"With a bit of luck and a strong ride, I can win overall," said Gonzalez.

Stage 20, Avila to San Martin de la Vega (141.2km):

1, Angelo Furlan, Italy, Alessio, 3 hours, 0 minutes, 8 seconds
2, Alessandro Petacchi, Italy, Fassa Bortolo, same time
3, Erik Zabel, Germany, Telekom, same time
4, Sven Teutenberg, Germany, Phonak, same time
5, Jan Svorada, Czech Republic, Lampre-Daikin, same time
6, Gerrit Glomser, Austria, Saeco, same time
7, Alexei Sivakov, Russia, Bigmat.Auber 93, same time
8, Andrej Hauptman, Slovenia, Tacconi, same time
9, Angel Edo, Spain, Maia-Milaneza, same time
10, Juan Guillamon, Spain, Jazztel, same time

General classification:

1, Roberto Heras, Spain, U.S. Postal, 74 hours, 24 minutes, 50 seconds
2, Aitor Gonzalez, Spain, Kelme, at 1:08
3, Oscar Sevilla, Spain, Kelme, at 1:45
4, Joseba Beloki, Spain, ONCE-Eroski, at 2:09
5, Iban Mayo, Spain, Euskaltel, at 4:15
6, Felix Garcia Casas, Spain, Bigmat.Auber 93, at 4:43
7, Francesco Casagrande, Italy, Fassa Bortolo, at 4:48
8, Gilberto Simoni, Italy, Saeco, at 6:12
9, Angel Casero, Spain, Team Coast, at 6:18
10, Manuel Beltran, Spain, Team Coast, at 7:08