Part-time pairing Lappi and co-driver Janne Ferm successfully navigated through 18 challenging snow stages to score a second career win with a 29.6-second margin over Toyota’s Elfyn Evans.
Lappi’s triumph ended a six and a half-year victory drought, arriving on the first start of his 2024 part-time programme.
M-Sport’s Adrien Fourmaux claimed a milestone maiden WRC podium, finishing 47.9s behind Lappi.
Hyundai’s Thierry Neuville finished fourth (+1m46.3s), while Oliver Solberg finished an impressive fifth overall (+5m04.2s) to secure the WRC2 class win on home soil.
Changeable weather conditions added to the challenge for crews as heavy snow showers helped turn the leaderboard on its head on Friday.
Returning reigning world champion Kalle Rovanpera, making the first start of his part-time programme with Toyota, started the event in ominous form, winning the opening two tests.
But his victory bid came to a halt when he lost control of his GR Yaris and crashed heavily into a snowbank on Friday’s stage four.
Hyundai’s Ott Tanak suffered a similar fate on the same stage, as the 2019 world champion exited Friday’s action from third, following a similar incident that damaged his i20 N’s radiator.
M-Sport’s Gregoire Munster also lost four minutes on the stage due to a puncture.
The demise of Rovanpera and Tanak handed Toyota’s Takamoto Katsuta an 11.4s lead over Lappi. Katsuta and Lappi then became locked in a head-to-head battle for the lead as heavy snow showers hampered those at the top of the road order.
Lappi managed to overhaul Katsuta for the rally lead on stage seven before ending Friday with a 3.2s advantage over the Japanese driver. Such were the effects of the heavy snow, WRC2 leader Oliver Solberg made history by ending the day sitting third overall.
Katsuta fought back in better conditions on Saturday morning, closing to within 0.9s of the Finn before his bid for a maiden win came to a dramatic end on stage 10.
Katsuta clipped a snowbank with the rear of his GR Yaris, which resulted in his car being fired deep into the snow and out of contention.
This handed Lappi a 1m31.6s lead over Fourmaux to protect across the final eight stages. Lappi also provisionally scored 18 points under the new points system for ending Saturday on top of the leaderboard. Fourmaux pocketed 15 points, Evans 13 and Neuville 10 points.
Lappi opted to back off to preserve his lead and his tyres on Sunday to claim his first win since Finland 2017.
Fourmaux, who won stage 11, survived a scare with a snowbank on stage 15 to head into the final day in second. He held a 16.7s margin over Evans, who managed to rise up from fifth on the leaderboard, after losing time to road position on Friday.
Evans started the rally second on the road but soon became the road sweeper when Neuville struggled to fire up his i20 N, which meant the Hyundai driver checked into Friday’s stage six four minutes late, incurring a 40s penalty.
There were suggestions of foul play to gain a road position advantage which were refuted by the Belgian, who revealed his car was suffering from a fuel pressure problem.
Evans was unable to overhaul the impressive Fourmaux across Saturday’s stages but did manage to leapfrog the Frenchman on Sunday as Evans pushed hard to top the Super Sunday classification.
Evans emerged fastest on the Sunday times with assistance from Rovanpera, to bag the bonus seven points.
Combined with his 13 from Saturday and four from the rally ending Power Stage after a slight error on the last corner cost him the extra point. It meant the Welshman claimed 24 points to outscore rally winner Lappi by five.
Neuville finished a distant fourth overall but managed to claim five Sunday points and three points from a wild Power Stage that ended with his i20 N losing its tailgate on a jump landing. He now leads Evans by three points in the championship standings.
Rovanpera, Tanak and Katsuta, who rejoined the rally after their crashes, left the weekend with points. Rovanpera picked up 11 points after winning the Power Stage and finishing second in the Sunday standings.
