Italian motorcyclist Luca Manca was critically injured in a fall during the sixth stage of the Dakar Rally on Thursday and was placed in an induced coma.
Officials at the Cobre de Calma hospital said he sustained critical head injuries and was breathing on a respirator. Officials described his condition as "life-threatening."
"These are critical injuries," said Dr. Miguel Cortes, who treated Manca following the accident. "He's on a ventilator and in an induced coma so we can keep him resting and so he does not fight the ventilator."
Manca crashed early in the 418-kilometre stage through the Atacama Desert in northern Chile from Antofagasta to Iquique.
He was praised following Wednesday's fifth stage for giving Spaniard Marc Coma a rear wheel so Coma could finish the stage.
In another accident on Thursday, Portuguese rider Paulo Goncalves of BMW broke his collarbone in a crash and withdrew.
The Dakar Rally is considered one of the most dangerous events in motor sports. On Saturday, a 28-year-old woman was killed when a vehicle taking part in the race veered off the course and hit her during the opening stage.
Last year, French motorcyclist Pascal Terry died during the rally.
AP