This year's Dakar Rally takes competitors from the Argentine port city of Mar de Plata all the way to Lima, Peru.
The 2012 Dakar Rally almost claimed its fourth life on Tuesday after a French motorcyclist was found unconscious in a section of remote sand dunes in western Argentina.
Sebastien Coue apparently crashed during the second stage in western Argentina and was exposed to temperatures above 104 degrees, Teodoro J. Schestakow Hospital said. His body temperature also exceeded 104.
"He entered in critical condition," hospital director Armando Dauverné said. "We don't know how long he was exposed to the sun. Right now he is in intensive care."
Joan Roma of Spain won the third stage while teammate Krzysztof Holowczyc of Poland led overall. Frenchman Cyril Despres captured the motorcycle stage to take first place overall after a navigational error by defending champion Marc Coma of Spain.
On Sunday, Argentine bike rider Jorge Martínez Boero died in a crash. On the same day, the pilot of an ultralight plane and his son died when the aircraft went down while following the race.
This is the fourth consecutive year the race is being held in South America. It had been run in Europe and Africa until the 2008 race was canceled because of fears of terrorism. The rally moved to South America the next year.
The past three years the race consisted of loop courses from Buenos Aires to Chile and back to Buenos Aires. This year the race began in Argentina, passes through Chile and finishes in Lima, Peru, on Jan. 15.
Roma won the 130-mile, high-altitude special from San Rafael to San Juan in 2 hours, 26 minutes, 51 seconds. He was 1:09 ahead of Holowczyc and 1:29 in front of last year's winner, Nasser Al-Attiyah in a Hummer.
For Roma, it was only his third stage win in a car but his 15th in race history.
In bikes, Despres took the 170-mile special stage in 3:48:38. He finished 8:37 in front of Frans Verhoeven of the Netherlands, and 8:39 faster than Portuguese Paulo Gonçalves.
More important, Despres was 10:12 ahead of his biggest rival, KTM teammate Coma. Coma, the leader after the second stage, took a wrong turn, lost 13 minutes and finished in seventh place.
"Yesterday was my day, but today definitely wasn't," Coma said.
Despres said: "It's good for my position, even if I'm never happy about other people's setbacks."
In the overall standings in bikes, France's David Casteu was third, 17:16 behind.
Based on reporting by the Associated Press.