Qatar's al-Attiyah takes the lead after Dakar prologue
The Toyota Hilux driver was 12 seconds quicker than Spain's three-times winner Carlos Sainz, driving the electric Audi RS Q e-tron, over the 19km timed sprint stage 1A before a 595km liaison between Jeddah and Ha'il.
South African Brian Baragwanath was in third place in a Century Racing buggy.
Audi -- with reigning champion and 14-times winner Stephane Peterhansel joining Sainz and Sweden's Mattias Ekstroem in the team -- is seeking to become the first manufacturer to win the Dakar with an electrified powertrain.
Peterhansel was ranked 14th in the car category after the prologue, one minute and 12 seconds off the pace, with Ekstroem 15th.
"We raced for 20km and got the race going. We're being very cautious and keeping tabs on all the parameters, but the car feels nice to drive," said Peterhansel.
"The car is good at going over dunes, which is also great."
Nine-times world rally champion Sebastien Loeb was fifth for the Bahrain Raid Xtreme team over the dirt tracks and small dunes.
The top 10 finishers in the car category in the prologue get to choose their starting position in the top 10 for Sunday's stage 1B, with Al-Attiyah having the final say on where he starts.
In the motorcycle category, Australian Daniel Sanders led the way for the Gas Gas factory team with Chile's Pablo Quintanilla second.
The Dakar, being run entirely in Saudi Arabia for the third time and featuring 409 vehicles at the start, is now in its 44th edition.
The annual rally started in 1978 as a race from Paris to the Senegalese capital, Dakar, but moved from Africa to South America for safety reasons in 2009.
One of motorsport's most dangerous and gruelling events, the rally moved to Saudi Arabia in 2020.