Ostersunds continued their amazing rise under English manager Graham Potter by beating Hertha Berlin to make it two wins from two in the Europa League.
They were in the Swedish fourth tier when Potter took over in 2011 and have been promoted three times before winning the Swedish Cup and qualifying for Europe for the first time.
Brwa Nouri scored the winner against the German side from a penalty.
Elsewhere, AC Milan needed an injury-time goal to beat Rijeka 3-2.
Milan led 2-0 at the San Siro through Andre Silva and Mateo Musacchio, but the Croat side scored twice in the last six minutes before 19-year-old Patrick Cutrone’s late winner in Group D.
Ukraine’s Zorya Luhansk moved up to second behind Ostersunds in Group J thanks to a 1-0 win at Athletic Bilbao, one of the pre-tournament favourites to win the Europa League.
Lazio striker Ciro Immobile scored his 12th goal in nine appearances this season as they beat Belgian club Zulte Waregem 2-0 in Group K.