South African Giniel De Villiers won Thursday's gruelling fifth stage of the Dakar Rally that left leading motorcyclist Kevin Benavides with a broken nose as he shattered his helmet jumping off a dune.

De Villiers completed the 456km special in his Toyota in 5hr 09min 25sec, finishing 0.58sec ahead of compatriot Brian Baragwanath, who has picked up another podium finish this year following second place on the prologue.

'Mr Dakar', aka 13-time winner Stephane Peterhansel rounded out the podium, stretching his lead in the overall standings over Nasser al-Attiyah to 6:11 after the Qatari finished fourth, 2:13 behind the Frenchman.

Defending champion Carlos Sainz is in third overall, 48:13 off the pace.

"Since the beginning things have not really been going our way, but today everything seemed to click," De Villiers said, calling the day's driving "a proper Dakar stage".

Stage 5 of the Dakar Rally between Riyadh and Al-Qaisumah in Saudi Arabia
Stage 5 of the Dakar Rally between Riyadh and Al-Qaisumah in Saudi Arabia AFP / FRANCK FIFE

"We took it a little bit calmer at the beginning just to make sure we got all the points. In some places the navigation was really, really difficult.

"We managed to do a good job today, so let's hope we can do a few more."

Al-Attiyah reckoned he had lost up to nine minutes in a frantic opening to the stage.

"Stephane did a very good job because he stayed behind me all the way," said Al-Attiyah, an Olympic skeet bronze medallist at the 2012 London Games.

"I'm quite happy to finish day five and tomorrow Stephane will open and it will be easier for me. We're taking it one day after another and we'll see where we are. Next week will also be very difficult."

Argentinian biker Kevin Benavides broke his nose in a crash before going on to win stage five of the Dakar Rally
Argentinian biker Kevin Benavides broke his nose in a crash before going on to win stage five of the Dakar Rally AFP / FRANCK FIFE

Peterhansel said the stage had been "really complicated... not really nice to drive".

"At the end it was not beautiful landscape and not nice to drive, but it was selective, a really selective stage like it always is on the Dakar."

In the motorbike category Benavides overcame a dramatic crash in the dunes that smashed his helmet and left him with a broken nose to win the stage, covering the 456km special in 5hr 09min 50sec.

A stage winner in the four previous Dakars, the Argentinian also leapfrogged Xavier De Soultrait by 2:31 to go top of the overall standings, having finished 7:55 ahead of the Frenchman in the stage.

"It was a really hard day for me," said Benavides, whose bloodied nose was bandaged post-race.

"At the beginning I got lost like all the riders, but after that I started to push a lot.

"On one dune I jumped, a big jump, and I crashed because I hit another big one with the front wheel. I banged my head ... and broke the GPS and everything. I cut myself too and started to lose a lot of blood. There was also some pain around my ankle."

Benavides pushed on, however, adding he was confident he could continue despite being in pain.

"I think I'll be okay for tomorrow," he said. "It was hard and there was a lot of pain today. But it's like that, this is the Dakar."

Meanwhile, organisers said Friday's sixth stage between Al-Qaisumah and Hail will be reduced by 100km "for safety reasons".

The decision was taken as several dozen competitors were still completing the fifth stage as night fell and weather conditions worsened.