Nine-times world rally champion Loeb, driving for the Bahrain Raid Xtreme team, inherited victory in the 345km special stage from Al Duwadimi to Riyadh after Audi's Carlos Sainz was handed a five minute penalty for speeding and dropped to third.
The stage win was Loeb's second of the 2023 Dakar and moved the Frenchman up to fourth overall in the car standings but one hour 52 minutes and six seconds behind Al-Attiyah.
The Qatari was second fastest on the stage and now leads South African team mate Henk Lategan by one hour three minutes and 46 seconds, with the rally ending in Dammam on Jan 15.
Monday is a rest day, with the rally then leaving Riyadh on Tuesday.
In the motorcycle category, Husqvarna's American Skyler Howes led Argentine rival Kevin Benavides, on a KTM, by a mere 13 seconds after a stage won by Botswana's Ross Branch for the Indian Hero team.