Championship leader Rovanperä put on a show in front of an army of flag-waving fans and posted the benchmark time on his fourth and final run of the 4.48km Rannankylä speed test.
He ended five-tenths clear of GR Yaris team-mate and fellow Finn Esapekka Lappi, with Hyundai i20 N star Ott Tänak completing the leading trio just four-tenths further back.
Soft compound Pirelli Scorpion tyres were the choice of all the leading drivers as light rain showers caused damp conditions early in the morning.
Lappi was fastest on the first run but relinquished the top spot to Rovanperä on the next pass. He moved back ahead after the third pass before Rovanperä bettered his time late in the session.
"Of course it's nice to be here at my home rally,” grinned Rovanperä. “Finally, we can have a normal Rally Finland with a lot of fans here.
"The feeling is good in the car and I am not feeling any pressure. It's more like excitement to see all the people cheering for us, so hopefully it's going to be a good weekend."
There were no dramas for Takamoto Katsuta, who finished 1.3sec down on the leaders to make it three Yaris cars in the top four. Hyundai youngster Oliver Solberg rounded off the top five despite an early spin and set identical pace with Toyota driver Elfyn Evans, who ended sixth.
Craig Breen led M-Sport Ford’s charge. He could only manage the seventh-fastest time and headed Puma colleague Pierre-Louis Loubet, while Thierry Neuville and Adrien Fourmaux completed the leaderboard.
The leading times were:
|1.||Kalle ROVANPERÄ||Toyota GR Yaris||1min 56.1sec|
|2.||Esapekka LAPPI||Toyota GR Yaris||+0.5sec|
|3.||Ott TÄNAK||Hyundai i20 N||+0.9sec|
|4.||Takamoto KATSUTA||Toyota GR Yaris||+1.3sec|
|Oliver SOLBERG||Hyundai i20 N||+1.7sec|
|6.||Elfyn EVANS||Toyota GR Yaris||+1.7sec|
|7.||Craig BREEN||Ford Puma||+2.0sec|
|8.||Pierre-Louis LOUBET||Ford Puma||+2.4sec|
|9.||Thierry NEUVILLE||Hyundai i20 N||+2.4sec|
|10.||Jari HUTTUNEN||Ford Puma||+3.1sec|
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