The eight-time world champion came through challenging damp and muddy conditions to preserve his lead, although Ogier's overnight advantage over championship leader Rovanpera was cut by 0.7s to 22.1s.
Hyundai’s Esapekka Lappi climbed into the podium positions, 1m18.4s adrift as Toyota’s Elfyn Evans dropped to fourth after losing time navigating a water splash.
Toyota’s Takamoto Katsuta headed to midday service in fifth (+2m13.6s) ahead of Hyundai’s Dani Sordo (+2m39.6s), and the M-Sport duo of Ott Tanak (+4m21.1s) and Pierre-Louis Loubet (11m01.4s).
Overnight rain created muddy and slippery conditions, increasing the difficulty for the crews that earmarked Saturday’s stages as the toughest of the rally.
This didn’t halt the rally leader Ogier in the day’s opening Soysambu (29.32km) stage, although it proved to be an eventful test for the Frenchman.
A puncture four kilometres from the end threatened to derail his effort, but Ogier still clocked a time 7.6s faster than nearest rival Rovanpera, who tried to be sympathetic to his GR Yaris.
There was further drama for Toyota as third-placed Evans stalled his GR Yaris following a rough entry to a water splash, an incident reminiscent to that the Toyota driver suffered in Sardinia.
The Welshman managed to reach the stage end, but dropped 45s as a result and slipped to fourth overall.
"I was very slow and tried to lift the front... I don't know," said Evans.
Hyundai’s Thierry Neuville rejoined the action following his retirement on Friday due to a broken suspension, but the Belgian wasn’t happy with his repaired i20 N.
"I don't know if it is the car or the road, but something is wrong. It is very hard to see the road, I struggled a lot," said Neuville.
If anything, the stage conditions were even more challenging in stage nine (Elementeita, 15.08km) as Rovanpera claimed a second fastest time of the rally. He shaved 0.6s from Ogier, who emerged as Rovanpera’s nearest rival.
"It's a proper challenge again. Quite rough in some places and I made one mistake as well. But all good," said Rovanpera.
Evans was third fastest, taking 0.2s back from Lappi as he started his recovery from the stall.
Rovanpera ended the morning with an impressive run through incredibly wet and muddy Sleeping Warrior stage, touted as the key test of the rally.
Rovanpera managed to successfully navigate through all the hazards to set a benchmark 3.5s faster than Lappi, who battled a slow puncture, while the reigning world champion's effort was 7.7s faster than a cautious rally leader Ogier.
"We could push a bit more, but for sure Seb is pushing a lot for this win," said Rovanpera. "In our case we need to think about the championship also, because the guys in the championship are much more behind and the good points are coming."
Lappi added that he had "never experienced anything like this before".
"When you see the puddles and mud, you brake and then you see if you survive," he said.
There were yet more woes for Evans, as a front left puncture contributed to him losing 22.2s and dropped him into the clutches of fifth-placed Katsuta.
Tanak also lost a whopping 43.7s in the stage, struggling for visibility after running out of windscreen washer fluid.
"It is a challenge to get through for sure," said the Estonian. "It was so muddy that I ran out of washer fluid so I had no visibility for the last 20km. It's what a Safari should be."
In WRC2, M-Sport’s Gregoire Munster leads the class ahead of a second run through the stages this afternoon.
