The result gave Despres the overall lead, 27 seconds ahead of Peterhansel and 5:44 clear of South Africa's Giniel de Villiers in a Toyota.
"That was a great day. It's the first time that our car has been in these conditions," Despres said. "Big, easy to climb dunes as well as very soft plateaus. We saw others stuck in the sand but we avoided that."
Overnight leader Nasser Al-Attiyah finished Sunday's stage almost 15 minutes off the pace in his Toyota after co-driver Matthieu Baumel fell ill.
Another to struggle was
Portuguese football manager Andre Villas-Boas was 44th out of 51 competitors to complete the course, more than three hours behind Despres.
In the motorcycle category, Spain's Joan Barreda took the overall lead with his 20th Dakar stage win.
Barreda clocked 2:56:44 on his Honda, 2:54 ahead of Yamaha rider Adrien Van Beveren of France.
