The championship leader was sitting third overall behind Evans and Ogier after the morning loop of stages, before tyre dramas struck his teammates in the afternoon.
Despite opening the road, Rovanpera won the final stage of the day to claim his third stage win of the event, putting him 14.6s ahead of team-mate Takamoto Katsuta.
Evans ended the day 22.4s adrift in third, while such was the attrition of the tough gravel event that Hyundai’s Ott Tanak managed to reach service in third spot, 25.3s behind, despite losing 36.4s to a snapped gear lever in the morning.
Toyota’s Takamoto Katsuta completed the day’s six stages in fourth ahead of Thierry Neuville, while Ogier dropped 2mins 21.6s to change a punctured left-rear, leaving the eight-time world champion in sixth overall.
Hyundai’s Oliver Solberg will start Saturday seventh overall, while Gus Greensmith was the only M-Sport team Ford Puma running in 12th after losing 13 minutes to a right rear puncture in the morning.
A disastrous day for M-Sport was compounded by Sebastien Loeb, Craig Breen and Adrien Fourmaux all suffering mechanical retirements. Loeb exited the rally in the morning after running out of EV power on a road section after losing internal combustion engine to a small fire.
The afternoon began with a lead change as the left-rear on Evans’ GR Yaris began to deflate seven kilometres from the stage end, costing the Welshman 18.7s and the rally lead.
Ogier won stage by 4.3s from Katsuta to move into an 8.2s lead over his Japanese teammate.
Rovanpera was third-fastest ahead of the recovering Tanak and Neuville, who lost time to gear shift problem and power loss in the morning respectively. Neuville was continuing to battle the drivability of his car during the afternoon.
Stage 5 did present drama as seventh-placed Fourmaux suffered a transmission issue putting him out of the day.
The following test saw Ogier extend his rally lead after winning Stage 6 by 0.4s from Katsuta, who continued to build on a strong display in the morning loop.
Rovanpera resumed his rapid pace to leapfrog Evans to third overall as Toyota extended its monopoly of the top four positions.
The day had one final twist courtesy of the second pass through the notorious 31.25km Kedong test, featuring deep sand that had hampered crews in the morning.
Despite teams questioning if it should go ahead given the difficulty to navigate through the sand, a decision was taken to run the stage.
The lead changed hands once again after Ogier punctured a left-rear on a 1.5km straight, 18 kilometres into the stage. The wheel change handed Rovanpera the rally lead as the Finn found a way through the sand to win the stage by 3.6s from Neuville.
Tanak was third-fastest as he climbed to third overall while a cautious Evans dropped 21.1s.
"It's so extreme,” said Evans. “I was careful and I was sure it would be a car graveyard! From my side it was important to try and get through. I lost a lot time with catching the dust in the hairpin."
Drivers were reduced to crawl in places such were the conditions and Katsuta lost even more time after coming to a stop to move around Breen, who became stranded on the edge of the road.
Katsuta lost even more time and came to a stop to negotiate the stranded Breen, who had suffered a puncture in the stage before a mechanical failure send him careering off the road at speed. But he was awarded a notional time by organisers that elevated him from fourth back to second.
The WRC field will return to action on Saturday to contest 150km of competitive kilometres split across six stages.
