Race leader Isidro Nozal edged out Britain's David Millar to win the 13th stage of the Tour of Spain.
Millar led the 53.3km time trial in Alabcete for some time having finished in one hour, two minutes, 16 seconds.
But Nozal produced a magnificent performance to post a time of 1:02.03 and extend his overall lead to three minutes, three seconds.
Fellow Spaniard Igor Gonzalez de Geldeano had a poor day and lost ground on Once team-mate Nozal.
13th stage results
1. Isidro Nozal, Spain, ONCE, 1 hour, 2 minutes, 3 seconds
2. David Millar, Britain, Cofidis, 13 seconds behind.
3. Serguei Ivanov, Russia, Fassa Bortolo, 0:40.
4. Bert Grabsch, Germany, Phonak, 0.44.
5. Claus Moller, Denmark, Milaneza, 0:45.
6. Igor Gonzalez De Galdeano, Spain, ONCE, 1:15.
7. Roberto Heras, Spain, US Postal, 1:45.
8. Santos Gonzalez, Spain, Domina Vacanze, 2:03.
9. Levi Leipheimer, United States, Rabobank, 2:14.
10. Antonio Tauler, Spain, Kelme, 2:23.
1. Isidro Nozal, Spain, ONCE, 41:56:32
2. Igor Gonzalez De Galdeano, Spain, ONCE, 3:03 behind.
3. Roberto Heras, Spain, US Postal, 5:13 behind.
4. Manuel Beltran, Spain, US Postal, 5:39 behind.
5. Francisco Mancebo, Spain, iBanesto.com, 7:12 behind.
6. Alejandro Valverde, Spain, Kelme, 7:50 behind.
7. Michael Rasmussen, Denmark, Rabobank, 8:44 behind.
8. Luis Perez, Spain, Cofidis, 8:49 behind.
9. Dario Frigo, Italy, Fassa Bortolo, 8:50 behind.
10. Unai Osa, Spain, iBanesto.com, 10:10 behind.