The reigning world champion seemed to be in control of the rally, winning five consecutive stages to open up a 5.7s lead over Toyota team-mate Elfyn Evans, despite starting first on the road.
However, the 22-year-old made a rare error resulting in his GR Yaris rolling onto its roof during the second pass of the fast and undulating Myhinpaa (stage eight) gravel test.
Rovanpera and co-driver Jonne Halttunen emerged from a heavily-damaged GR Yaris without injury.
The world championship leader admitted he was shocked by the accident having driven cleanly and within his comfort zone up until the incident.
“It was quite a, let’s say, stupid crash. We just went into one right hander and the speed was fine and after the braking it felt the corner was going to be good,” said Rovanpera.
“I didn’t expect anything to happen and I don’t know maybe the small [lower class] cars line [in the road] was really narrow and I went on some s**t and it was a big slide that I couldn’t correct.
When asked if there was anything he could have done to save the car, he added: “It was actually the first time in a long time that I had something to do which is always a big shame. Normally you go through somewhere fast and you know you made a mistake but it went and that was it. I tried to correct it and couldn’t do it.”
As Finland’s first world champion since 2002, Rovanpera carried a weight of expectation on his shoulders as a large crowd hoped to witness a first Finnish winner at the event since Esapekka Lappi’s triumph in 2017.
Reflecting on missed opportunity to claim a first Rally Finland win, he said “It is disappointing because the lead was going quite well and the driving was quite easy and I didn’t overpush.
“I didn’t really have any moments and then we go out like this is always a shame.”
Rovanpera’s premature exit has handed Evans the rally lead from Hyundai’s Thierry Neuville with Toyota's Takamoto Katsuta in third.
It is unclear at this stage if Rovanpera’s GR Yaris can be repaired to allow the Finn to rejoin the rally on Saturday.
Update: Rovanpera's name appeared on the start schedule for Saturday but the team has confirmed the car has sustained too much damage to return to action this weekend.
In the service of car #69 it was found that the damage to the chassis was too much to repair and we unfortunately have to retire it from the event.#ToyotaGAZOORacing #WRC #RallyFinland pic.twitter.com/rSSVX7tgCj
— TOYOTA GAZOO Racing WRT (@TGR_WRC) August 4, 2023
