Venezuela's Unai Etxebarria claimed victory in the fourth stage of the Tour of Spain from Santander to Burgos.
The Euskaltel rider attacked from a breakaway group of eight with 20 kilometres left to finish 44 seconds clear of his team-mate, Spaniard David Etxebarria.
"With David in the break it was much easier," said Etxebarria. "He could control the other riders."
Spain's Isidro Nozal of the ONCE team, also present in the break, is the new race leader after the 151km ride from Santander.
"I hope to hold on to the leader's jersey at least as far as the time trial in Zaragoza on Thursday," he said. "Then my team leader Igor Gonzalez de Galdeano could take over again."
Stage four, Santander to Burgos
1 Unai Etxebarria (Ven) Euskaltel three hours 36 minutes 51 seconds
2 David Etxebarria (Spa) Euskaltel 44 seconds behind
3 Felix Cardenas (Col) Labarca-2 Cafe Baque same time
4 Jose Luis Gutierrez (Spa) Kelme
5 Jurgen Van Goolen (Bel) Quickstep
6 Isidro Nozal (Spa) Once-Eroski
7 Oscar Laguna (Spa) Colchon Relax-Fuenlabrada
8 Erik Zabel (Ger) Telekom Team, 1:32 behind
9 Julian Dean (NZ) Team CSC same time
10 Patrick Calcagni (Switz) Saunier Duval-Vini Caldriola
Overall Standings (after four of 21 stages)
1 Isidro Nozal (Spa) Once-Eroski 10 hours 51 minutes 35 seconds
2 David Etxebarria (Spa) Euskaltel 50 seconds behind
3 Joaquin Rodriguez (Spa) Once-Eroski same time
4 Igor Gonzalez de Galdeano (Spa) Once-Eroski
5 Marcos Serrano (Spa) Once-Eroski
6 Manuel Beltran (Spa) US Postal 1:00 behind
7 Roberto Heras (Spa) US Postal same time
8 Aitor Osa (Spa) iBanesto.com 1:14
9 Francisco Mancebo (Spa) iBanesto.com same time
10 Unai Osa (Spa) iBanesto.com