Spain's Angel Vicioso gave a welcome boost to the beleaguered Astana-Würth team Tuesday as he held off a furious late charge from the peloton to claim the fourth stage of the Tour of Switzerland in La Chaux-de-Fonds.

Belgium's Nick Nuyens, Monday's stage three winner, retained the overall leader's jersey after finishing in the pack, one second behind Vicioso.

Vicioso and fellow escapee David Herrero (Euskaltel-Euskadi) took off from the peloton with just 6km left to ride in the 161.3km stage and held firm until the finish line, with Vicioso just edging out his compatriot.

It was a welcome respite for the Astana-Würth team, which is being threatened with expulsion from next month's Tour de France over allegations of taking part in a blood-doping scandal.

But the Spaniard was given little time to enjoy his victory and was quickly forced into fielding questions about his involvement in the sorry affair.

When questioned about his association with Dr. Eufemiano Fuentes, the head doctor at the laboratory involved in suspected blood-boosting, Vicioso went on the defensive.

Rabobank chases with an assist from Der Kaiser

Photo: Graham Watson

"Am I a client of Dr. Fuentes? I don't want to answer that question. I am happy to answer all questions about the stage, but not that one," he said. "It's Würth's first victory. I am happy to have brought it to the team, it's a team that has put a lot of faith in us."

Former team manager Manolo Saiz, who was in charge when Astana was known as Liberty Seguros-Würth, before the American insurance company dropped its sponsorship over the affair, was one of two team bosses arrested after a crackdown on drugs in cycling by Spanish authorities. He later resigned his post.

The other team, Comunidad Valenciana, whose boss Jose Ignacio Labarta likewise resigned after his arrest, was kicked out of the Tour de France on Tuesday.

But 29-year-old Vicioso left all those troubles behind as he joined Herrero on a break, after several other efforts throughout the day had failed, and held off the hard-riding peloton. Rabobank drove the chase, hoping to set up team leader Michael Rasmussen for the victory, but simply ran out of road, and Herrero and Daniele Bennati (Lampre-Fondital) both charged across the line head of the Dutch team's Spanish sprinter.

Nuyens dropped off the back of the peloton at one stage, but recovered well to finish 11th in the stage. "It wasn't easy, especially on the final climb," Nuyens said. "But my team was there for me from the start, and so I could defend the yellow jersey."

Stage 4
1. Angel Vicioso (Sp) Astana-Würth, 161.3km in 3:45:09
2. David Herrero (Sp), Euskaltel-Euskadi, s.t
3. Daniele Bennati (I), Lampre-Fondital, at 0:01
4. Oscar Freire (Sp), Rabobank, s.t.
5. Allan Davis (Aus), Astana-Würth, s.t.
6. Cristian Moreni (I), Cofidis, s.t.
7. Michael Albasini (Swi), Liquigas, s.t.
8. Erik Zabel (G), Milram, s.t.
9. Beat Zberg (Swi), Gerolsteiner, s.t.
10. Kim Kirchen (Lux), T-Mobile, s.t.

Overall
1. Nick Nuyens (B) Quick Step, 16:15:19
2. Daniele Bennati (I), Lampre-Fondital, at 0:02
3. Linus Gerdemann (G), T-Mobile, s.t.
4. Jorg Jaksche (G), Würth, at 0:05
5. Angel Vicioso (Sp), Astana-Würth, at 0:13
6. Michele Albasini (Swi), Liquigas, at 0:15
7. Koldo Gil (Sp), Saunier Duval-Prodir, at 0:16
8. David Herrero (Sp), Euskaltel-Euskadi, at 0:17
9. David de la Fuente (Sp), Saunier Duval-Prodir, at 0:18
10. Gregory Rast (Swi), Phonak, s.t.