Sainz grew to become the third completely different Mini driver to win a stage of the Saudi Arabia-based occasion, as he set the tempo over the 427km loop round Neom in his buggy.
His closing profitable margin on the day was three minutes and 31 seconds over reigning champion Nasser Al-Attiyah, and he heads the Toyota driver by 5 minutes within the general classification.
Stephane Peterhansel, who drives the opposite X-raid buggy, matched Sainz for tempo for a lot of the stage, solely to lose 10 minutes within the closing stretch.
As such, Yakub Przygonski and privateer Yasir Seaidan accomplished the highest 4 on the day in a pair of four-wheel-drive Minis.
Two-time System 1 champion Fernando Alonso, who had misplaced over two hours to repairs on Monday, was fifth-fastest as he completed the stage simply six minutes slower than Sainz.
In a single day chief Orlando Terranova misplaced 13 minutes to Sainz however stays inside the prime three general, and has over 10 minutes in hand to Toyota driver Yazeed Al-Rajhi and Peterhansel.
Mathieu Serradori, who drives a Century CR6 buggy, gave up 20 minutes however stays a powerful sixth and is marginally forward of Monday stage winner Giniel de Villiers (Toyota).
Former World Rally Championship common Khalid Al Qassimi, who had entered the day in seventh place, demolished his privateer Peugeot in a roll 300 kilometres into the stage and exited the marathon.
Additionally dropping out was returnee Vladimir Vasilyev, who appeared on target to enter the highest 10 within the normal classification earlier than his X-raid Mini caught fireplace.