Eight-time world champion Ogier started the day 0.1s behind overnight leader Tanak but headed to midday service with a 2.5s lead over Toyota team-mate Kalle Rovanpera.
Elfyn Evans completed the loop in third, 19.5s adrift, but ahead of Hyundai’s Thierry Neuville, who endured an eventful morning to reach service 21.5s back.
Toyota’s Takamoto Katsuta sat in fifth (+29.1s) in front of Esapekka Lappi (+41.1s), Dani Sordo (+45.9s), Pierre Louis Loubet (+1m17.3s), Tanak (+2m26.4s) and WRC2 runner Oliver Solberg (+2m49.6s).
Overcast conditions punctuated with some light rain created damp roads for the drivers to navigate.
The dampness was the least of the driver’s concerns as Kenya’s unique wildlife became a more important variable as stage two (Loldia, 19.17km) began.
Hyundai’s Neuville was distracted by a bee that had entered the cockpit of his car, which caused the Belgian to lose his concentration momentarily.
“It's very shaky in there and we got kicked off the line and we had a big bee in the car," said Neuville, who clocked the third fastest time.
“Basically I lost my concentration in the beginning and there was a lot of cleaning in the last section.”
Overnight leader Tanak started the stage strongly, but lost his lead when he came across a pig and a group of zebras that resulted in the Estonian crossing the finish line 15.2s adrift.
“It has been like driving in a zoo. First, we met a pig in the road and then we had a group of zebras who didn’t give a f*** that we were coming,” said Tanak.
Zebras also delayed Sordo’s progress, but his encounter wasn’t as costly as Tanak’s, as the Spaniard dropped 11.7s.
M-Sport’s Pierre-Louis Loubet had a clean run through the stage, but his Ford Puma was down on power due to a setting issue which resulted in a 34.5s time loss.
The stage was won by Ogier, who stormed into the lead after setting a head-turning benchmark time, 7.5s faster than nearest rival and Toyota team-mate Rovanpera.
“I tried to have a decent speed but nothing crazy because there's a long weekend ahead," said Ogier, who assumed the rally lead.
The middle stage (Geothermal 13.12km) of the morning loop was a more traditional test, which suited Kenya debutant Lappi. The Finn took the stage win by 1.2s from Ogier.
“The stage here is clear and more like Finland style as well,” said Lappi. “On the previous one, the guys made big cuts which I didn't do, so for sure I lost a lot of time over there. I think the next 10 stages are not so simple.”
Katsuta impressed to set the third fastest time, 2.3s shy and a second faster than next best Rovanpera.
There was however drama for Neuville, who shipped 12.5s to a slow front-right puncture, while his team-mate Sordo also battled with the handling of his i20 N.
Tanak’s slow start continued, but it was the handling of his Puma and not the wildlife that was costing him time. He dropped 9.3s, 2.2s slower than his team-mate Loubet, who managed to rectify the power issue that hampered him in the previous test.
Rovanpera took the honours in the final stage of the loop, a brutal pass through the Kedong (30.62km) test. The Finn was 8.0s faster than Neuville, who completed a tyre change on the road section.
Rovanpera looked on course to take the overall rally lead from Ogier, who was without hybrid on the stage, but the Frenchman managed to hold onto the advantage.
He wasn’t the only driver to hit trouble though, as Tanak suffered with a tyre that had come away from the rim, necessitating a wheel change mid-stage that cost him 2m12.6s. Lappi also suffered a right rear puncture, but managed to nurse the car to the end while losing 30.3s.
Katsuta lost time with “big damage” to the front of his GR Yaris that required a repair before the stage start, which dropped the Japanese one place to fifth.
Crews will complete a second pass of the stages this afternoon to complete Friday’s action.
