Tanak left the road halfway into the morning’s second stage, the 12.8-mile Saint-Clement-sur-Durance – Freissinieres SS4 test.
Tanak ran out of road at high speed exiting a right-left kink and his i20 Coupe WRC dropped down a ditch then entered a lengthy barrel roll.
Both Tanak and co-driver Martin Jarveoja appeared unharmed as they exited the car.
Tanak was placed fourth overall at the start of the stage, 10.3 seconds behind the leader, his teammate Thierry Neuville.
Neuville however lost the lead of the rally on SS4 to Toyota’s Elfyn Evans who has topped both of the Friday morning stages so far on his debut for the team. Evans now sits 3.4s clear of Neuville and 5.5s clear of six-time Monte Carlo rally winner Sebastien Ogier in third, who also is making his Toyota debut.