Mini buggy driver Sainz, whose son and namesake races in Formula One for McLaren, finished third in Thursday's 379km stage over desert dunes from Shubaytah to Haradh.
"It's good to have put the marathon stage behind us," commented Sainz.
"Yesterday we got to work on the car and everything went well. Just one day to go. I'll keep an eye on the gaps and stay focused for tomorrow."
Sainz's French team mate Stephane Peterhansel, a 13-times Dakar winner on two wheels and four, won the stage -- his fourth victory on this year's event and career 80th.
He is now just six seconds behind Toyota's Al Attiyah going into the final 374km to Qiddiya with the pair gaining eight minutes on Sainz, the first driver to start the 11th stage.
"We paid dearly for our mistake yesterday. Now we'll battle Stephane for second place," said Al Attiyah.
Saudi Arabian driver Yazeed Al-Rajhi was fourth overall in a Toyota.
Two-times Formula One champion Fernando Alonso was 113th in the running order at the day's start, after rolling his Toyota Hilux and losing an hour on Wednesday, and finished eighth fastest to end 13th overall.
"Yesterday we had a low-speed roll-over, it was not big. Today we had no issues. It was a good marathon stage," said the Spaniard.
"Starting 113th in the classification didn't help. I'm very happy. You learn things every day. One day left to finish my first Dakar."
In the motorcycle category, Honda's American rider Ricky Brabec is poised to end KTM's 18-year dominance of the endurance event.
Brabec was nearly 14 minutes clear of Chilean Pablo Quintanilla, the stage winner, on a Husqvarna with Australia's defending champion Toby Price third for KTM but with 22 and a half minutes to make up on the lead.
"It's been a good stage and at the moment Honda just needs to protect their lead. The guys are riding fast and riding smart. It's definitely making it hard for us to try and make up that gap," said Price. (Reporting by Alan Baldwin in London, editing by Christian Radnedge)