The M-Sport-Ford driver produced a committed run through the 3.48km mixed surface Harju test, held on streets and parkland roads within the host city of Jyvaskyla.
Tanak clocked a time 0.6s faster than Hyundai’s Thierry Neuville, while championship leader Kalle Rovanpera was a tenth further back to clock the third fastest time.
"The ones we are fighting are very strong obviously – we need to put everything on the line,” said three-time Finland winner Tanak at the stage end, when asked if he had the package to win this weekend.
Thousands of fans flocked to the super special stage mainly to witness the homecoming of world champion and Jyvaskyla local Rovanpera.
The Finn was however fortunate not to lose more than 0.7s after sliding wide navigating an asphalt left hander, that resulted in his Toyota GR Yaris grazing a kerb. The championship leader was fastest on the day’s shakedown stage earlier this morning.
“The kerb was not so bad, it was quite small so I knew it was not a bad hit,” said Rovanpera, spurred on by the home support.
“An amazing feeling – I can almost hear the people from inside of the car, I know how loud it is. It feels so amazing in the car when you know the atmosphere is so great.”
Hyundai’s Esapekka Lappi set the fourth fastest time, 1.8s adrift of Tanak. The Finn was 0.1s faster than Toyota’s Elfyn Evans.
M-Sport’s Pierre-Louis Loubet managed to beat Toyota’s Takamoto Katsuta to sixth ahead of the third factory Hyundai i20 N driven by Finn, Teemu Suninen.
The Rally1 field was completed by 18-time WRC rally winner Jari-Matti Latvala, making a one-off return to rallying’s top tier in a fourth GR Yaris.
The Toyota WRC team principal began the rally having only completed one test day in the Rally1 car. Latvala was 8.1s slower on the stage and 0.2s faster than top WRC2 runner Jari Huttunen, who rounded out the top 10.
Nine gravel stages await the crews on Friday, comprising 104.76 kilometres.
| Cla | Driver | Car / Engine | Time | Gap |
| 1 | Ott Tänak | Ford | 2'39.0 | |
| 2 | Thierry Neuville | Hyundai | 2'39.6 | 0.6 |
| 3 | Kalle Rovanperä | Toyota | 2'39.7 | 0.7 |
| 4 | Esapekka Lappi | Hyundai | 2'40.8 | 1.8 |
| 5 | Elfyn Evans | Toyota | 2'40.9 | 1.9 |
| 6 | P-L.Loubet | Ford | 2'41.2 | 2.2 |
| 7 | Takamoto Katsuta | Toyota | 2'42.1 | 3.1 |
| 8 | Teemu Suninen | Hyundai | 2'43.6 | 4.6 |
| 9 | J-M.Latvala | Toyota | 2'47.1 | 8.1 |
| 10 | Jari Huttunen | Skoda | 2'47.3 | 8.3 |
