By Alasdair Fotheringham
HARO, Spain (Reuters) - Juan Jose Haedo claimed Argentina's first grand tour stage win on Tuesday following a chaotic bunch sprint in the Tour of Spain while Spaniard Juan Jose Cobo retained the overall lead.
After several riders at the head of the field nearly strayed off course at a roundabout 300 meters from the finish in Haro, Haedo went the right way round to claim victory.
Italians Alessandro Petacchi and Daniele Bennati were second several bike lengths behind the 30-year-old Saxo Bank rider.
"There was a lot of confusion, everybody braked but I got round okay, I went the right way," Haedo told reporters.
"It wasn't totally clear what we had to do and I got lucky. I've specially wanted a win in the Tour of Spain because I live in Spain and to be the first rider from Argentina to win a stage in a major tour is a real breakthrough, a key moment in my career.
"I'll try again in Madrid, which is the last sprint left in this race, and if I can get a top 10 in the world championships in September, I'll be more than satisfied with my year."
Cobo, 10th on the flat, long stage across the sunbaked plains of northern Spain, starts the sixth and final summit finish on Wednesday with a 22-second advantage over Britons Chris Froome and Bradley Wiggins, both of the Sky team who are second and third respectively.
Having grown up just an hour's bike ride away from the short but steep six kms climb of Pena Cabarga near the Cantabrian coast, the 30-year-old Geox rider told reporters he anticipated a great deal of local support.
"It's a really tough climb, but I will be surrounded by my people, that will be great moral support," Cobo said.
"Today was tricky with the wind in the final kilometers, but I came through better than expected."
Spanish overall contender and points competition leader Joaquim Rodriguez was caught in a pile-up some 12 kms from the line and injured his left arm, losing over 11 minutes.
"There was a big crash, loads of people fell, I don't know if I'll be able to continue tomorrow," Rodriguez, fourth in 2010, said before heading to hospital for a checkup.
Classics specialist and 2005 world champion Tom Boonen of Belgium did not start Tuesday's stage after injuring his hand earlier in the race. The race finishes in Madrid on Sunday.
(Editing by John Mehaffey)