Haro - Argentina's Juan Jose Haedo of the Saxo Bank team won the 16th stage of the Tour of Spain on Tuesday while Spain's Juan Jose Cobo of Geox retained the leader's red jersey.
Haedo beat Italy's Alessandro Petacchi of Lampre to the line in a sprint finish after a relatively flat 203.6km ride from Villa Romana La Olmeda to Haro in northern Spain.
Third was another Italian, Daniele Bennati of Leopard Trek.
Cobo, who finished 10th, 10 seconds behind the stage winner, holds a 20-second lead over Britain's Chris Froome of the Sky Team in the overall standings.
Another Briton, Bradley Wiggins, also of Sky, remains third overall, 51 seconds behind Cobo.
Froome and Wiggins finished 13th and 22nd respectively on Tuesday.
Haedo admitted he was lucky in the last km.
The final sprint took the riders around a traffic circle, but some, such as Slovakia's Peter Sagan of Liquigas, ended up taking it in the wrong direction.
"Until today, I had very few chances to win a sprint," said Haedo. "But today I managed it.
"The truth is that, in the course book, it was not specified that you can only go round the traffic circle to the left. I was lucky."
The stage was marked by several crashes, one of which involved Spain's Joaquim Rodriguez of Katusha, who finished the stage 11 minutes behind the leader and went immediately to hospital for tests.
Italy's Alessandro Spezialetti of Lampre suffered a fractured collarbone and withdrew.
Switzerland's Fabian Cancellara of Leopard Trek also announced he intended to withdraw from the Tour, but to return home in order to prepare for the World Championships in Copenhagen.
Three riders - 21-year-old Spaniard Antonio Cabello of AGC, his compatriot and team-mate Jesus Rosendo and Frenchman Julien Fouchard of Cofidis - staged an early breakaway and together built up a lead of more than eight minutes.
But Cabello and Fouchard were caught with some 15 kms from the finish and Rosendo a few kms later.
Wednesday's 17th stage takes the riders 211kms from Faustino V to Pena Cabarga, a hilly route that ends by the coast in the northern region of Cantabria.
Results after Tuesday's 16th stage of the Tour of Spain, a 203.6km ride from Villa Romana La Olmeda to Haro:
1. Juan Jose Haedo (ARG/SAX) 4hr 41min 56sec
2. Alessandro Petacchi (ITA/LAM) at 0:00.
3. Daniele Bennati (ITA/LEO) 0:00.
4. Vicente Reynes (ESP/OLO) 0:00.
5. Leigh Howard (AUS/HTC) 0:02sec
6. Koen de Kort (NED/SKS) 0:02.
7. Lloyd Mondory (FRA/ALM) 0:02.
8. Nikolas Maes (BEL/QST) 0:02.
9. Chris Sutton (AUS/SKY) 0:02.
10. Juan Jose Cobo (ESP/GEO) 0:02.
11. Nicolas Roche (IRL/ALM) 0:04.
12. Greg Van Avermaet (BEL/BMC) 0:04.
13. Chris Froome (GBR/SKY) 0:04.
14. Vincenzo Nibali (ITA/LIQ) 0:04.
15. Jakob Diemer Fuglsang (DEN/LEO) 0:04.
16. Serguey Lagutin (UZB/VAC) 0:04.
17. Nico Sijmens (BEL/COF) 0:04.
18. Daniel Moreno (ESP/KAT) 0:04.
19. Bauke Mollema (NED/RAB) 0:07.
20. Maxime Monfort (BEL/LEO) 0:07.
1. Juan Jose Cobo (ESP/GEO) 64hr 39min 14sec
2. Chris Froome (GBR/SKY) at 0:22sec
3. Bradley Wiggins (GBR/SKY) 0:51.
4. Bauke Mollema (NED/RAB) 1min 41sec
5. Maxime Monfort (BEL/LEO) 2:40.
6. Denis Menchov (RUS/GEO) 3:06.
7. Jakob Diemer Fuglsang (DEN/LEO) 3:08.
8. Vincenzo Nibali (ITA/LIQ) 3:49.
9. Jurgen Van den Broeck (BEL/OLO) 4:03.
10. Wout Poels (NED/VAC) 4:18.
11. Daniel Moreno (ESP/KAT) 4:34.
12. Mikel Nieve (ESP/EUS) 4:55.
13. Sergio Pardilla (ESP/MOV) 6:01.
14. Chris Anker Sorensen (DEN/SAX) 6:13.
15. Daniel Martin (IRL/GRM) 6:47.
16. Serguey Lagutin (UZB/VAC) 7:52.
17. Kevin Seeldraeyers (BEL/QST) 8:07.
18. Nicolas Roche (IRL/ALM) 9:18.
19. Marzio Bruseghin (ITA/MOV) 9:18.
20. Carlos Sastre (ESP/GEO) 10:54.