Roberto Heras swept into the overall lead in the Tour of Spain with a brilliant performance against the clock that gave him a time-trial victory in Saturday's penultimate stage.
Heras's ride virtually assures him overall victory
The US Postal rider, winner of the event in 2000 and runner-up a year ago, set out from San Lorenzo de El Escorial trailing race leader Isidro Nozal by one minute 55 seconds.
But he covered the hilly 11.2km (seven miles) to the finish in Alto de Abantos two minutes 23 seconds quicker than his rival to virtually guarantee victory when the race concludes on Sunday in Madrid.
Heras turned up the heat on ONCE rider Nozal on Friday, when he took more than a minute out of his lead after stepping up the pace of stage 19's final climb.
And he pounced at precisely the right moment on Saturday with a devastating display in the time-trial that turned his deficit into a 28-second advantage.
The Spaniard is now almost certain of winning the Tour, as there are no time bonuses up for grabs on the final day.
Nozal had led the race for 16 days and the yellow jersey had been in ONCE hands since stage one, with his team-mates Igor Gonzalez de Galdeano and Joaquin Rodriguez having preceded him on top of the general classification.
Alejandro Valverde's second place in the time-trial confirmed his rising star potential and took him into third overall at the expense of Gonzalez de Galdeano.
Stage 20 result
1. Roberto Heras (Spa) US Postal, 25 minutes, 8
2. Alejandro Valverde (Spa) Kelme, at 14 seconds
3. Felix Cardenas (Col) Labarca-2, same time
4. Fabian Jeker (Swi) Milaneza, 15 seconds
5. Santos Gonzalez (Spa) Domina Vacanze, 22 seconds
6. Roberto Laiseka (Spa) Euskaltel, 32 seconds
7. Dario Frigo (Ita) Fassa Bortolo, 34 seconds
8. Levi Leipheimer (US) Rabobank, 48 seconds
9. Oscar Sevilla (Spa) Kelme, 58 seconds
10. Unai Osa (Spa) iBanesto.com, 1:03
12. David Millar (Gbr) Cofidis, 1:09
26. Isidro Nozal (Spa) ONCE-Eroski, 2:23
1. Roberto Heras (Spa) US Postal, 65 hours, 40 minutes, 33 seconds
2. Isidro Nozal (Spa) ONCE-Eroski, at 28 seconds
3. Alejandro Valverde (Spa) Kelme, at two minutes 25 seconds
4. Igor Gonzalez de Galdeano (Spa) ONCE, 3:27
5. Francisco Mancebo (Spa) iBanesto.com, 4:47
6. Manuel Beltran (Spa) US Postal, 5:51
7. Michael Rasmussen (Den) Rabobank, 5:56
8. Felix Cardenas (Col) Labarca-2, 6:33
9. Unai Osa (Spa) iBanesto.com, 6:51
10. Luis Perez (Spa) Cofidis, 7:56