France's Stephane Peterhansel reclaimed the Dakar Rally lead as his main rivals Hiroshi Masuoka and Colin McRae lost valuable time with mechanical trouble.
Peterhansel took advantage of his rivals' problems
Peterhansel won the 355-kilometre eighth stage between Atar and Tidjikja ahead of Germany's Jutta Kleinschmidt and Belgian Gregoire De Mevius.
Overnight leader Masuoka fell to third, losing an hour with gearbox problems.
And McRae was forced to wait for help after suffering serious mechanical problems with his Nissan.
The Scot finished more than three hours off the pace and dropped from third to eighth in the overall rankings.
Masuoka, who is chasing his third successive Dakar win, was overtaken in the overall standings by De Mevius.
The Japanese driver revealed before the start of the stage that a Mauritanian soldier had pointed a gun at him the previous day to demand money when he entered the country.
Spain's Nani Roma, on a KTM, won the motorcycle stage, with France's Jean Brucy second and Richard Sainct third.
Roma inherited the overall lead with an advantage of eight minutes and 16 seconds over Sainct after previous leader Cyril Despres dropped to seventh.
Despres lost his way in the desert after falling and accidentally unplugging his GPS
positioning system. He then ran out of fuel.
"It was the worst day of my life," said Despres. "There are days when everything goes wrong."
A search party has been sent to rescue Britain's Nick Plumb after the Team Dome BMW rider failed to report for the start of the stage.
He is believed to have spent last night alone in the desert.
Plumb suffered battery failure during stage six on Tuesday and as a result arrived too late at the checkpoint to get any sleep before Wednesday's seventh stage.
He had further battery problems on Wednesday and split up from team-mate Simon
Pavey several kilometres from the checkpoint.
He was not picked up by the sweeper vehicle, and race organisers sent a helicopter to find him after receiving a call from Plumb's satellite phone.
Friday's ninth timed stage is 736km from Tidjikja to Nema in eastern Mauritania.
Overall positions after stage eight:
1. Stephane Peterhansel (Fra) Mitsubishi
at 18 hours 54 minutes 5 seconds
2. Gregoire De Mevius (Bel) BMW +1hr 4mins 38secs
3. Hiroshi Masuoka (Jpn) Mitsubishi +1:22:32
4. Jean-Louis Schlesser (Fra) Schlesser Ford +1:29:42
5. Luc Alphand (Fra) BMW +2:50:07
1. Nani Roma (Spa) KTM
at 21 hours 4 minutes 40 seconds
2. Richard Sainct (Fra) KTM +8mins 15secs
3. Jean Brucy (Fra) KTM +14:25
4. Alfie Cox (SA) KTM +51:19
5. Pal Anders Ullevalseter (Nor) KTM +1:01:06