(Reuters) - Defending motorcycle champion Toby Price withdrew from the Dakar Rally on Thursday after fracturing his left thigh bone in a high-speed fall on the fourth stage in Bolivia.
The Australian was airlifted to hospital after losing control of his KTM and falling after 371 km of a stage he had looked like winning.
Spaniard Joan Barreda finished with a hefty 22-minute lead in the bikes category after the high-altitude stage to Tupiza, with Price's Austrian team mate Matthias Walkner taking the day's honours.
However Barreda was then handed an hour penalty for refuelling his Honda in a prohibited area, a sanction that lifted Pablo Quintanilla into the lead.
In the car category, five times bike champion Cyril Despres of France took his first stage win and wrested the overall lead from compatriot and fellow Peugeot driver Sebastien Loeb.
Loeb, Spanish team mate Carlos Sainz and defending champion Stephane Peterhansel all lost time, with the latter losing his way as well, allowing Despres to vault from fifth overnight to first.
On a day that saw two times winner Nasser Al-Attiyah of Qatar retire from the event after damaging his car on Wednesday, Sainz's continued involvement also looked doubtful after he rolled his Peugeot and became stuck in a ravine.
Sainz, double rally world champion and father of the Formula One driver who is his namesake, crossed the finish line two hours and 19 minutes behind Despres and may have to withdraw for the fifth time in a row.
"I don't think we can repair the car because it's badly damaged but they are looking at it," said Sainz, who suffered back pain after the crash. "In any case, I'm not sure I can continue."
Despres leads Peterhansel by four minutes and eight seconds overall with Loeb dropping to fourth place, six minutes and 48 seconds off the lead.
Reporting by Alan Baldwin in London, editing by Toby Davis