Ambri-Piotta's lead in Switzerland's first division ice hockey league has been diminished with Langnau Tigers beating them 4-1.
Ambri's defeat on Tuesday puts them just two points away from second-placed Zug, and three points away from ZSC Lions.
The match between the Ticino side and Langnau had historical dimensions. It was this season's first home win for the Tigers and their first victory against Ambri since the early 1980s.
Ambri's run of six consecutive wins was halted when Langnau's fortunes took a turn for the better in the middle of the second period. Stéphane Lebeau had equalised for Ambri, but then Dan Gauthier put Langnau in front again.
Another goal by Langnau's Vlastimil Plavucha just three minutes from the end of the match, followed by a second goal from Gauthier sealed the Tigers' victory.
In other matches, Zug beat Berne 2-0 at home, allowing them to consolidate their strong position in the league. Fribourg are still struggling to make much progress, having only managed to just scrape past Chur, 1-0.
The other Ticinese side, Lugano, dealt a blow to La Chaux-de-Fonds by beating them 3-1 away, and relegating them to the bottom of the league table.
Davos came away with a 3-0 away win against Rapperswil, while Zurich Lions narrowly beat Kloten 2-1.
swissinfo with agencies