Fredrik Sjovold and Kasper Hogh were on target as Bodo/Glimt earned a famous 2-1 win over Atletico Madrid at the Riyadh Air Metropolitano to book a spot in the Champions League play-off round.
Alexander Sorloth put the hosts ahead against the side from his native Norway in the 15th minute, but Sjovold levelled proceedings before the break.
Hogh then scored the winner just before the hour, as Bodo crept into 23rd to book a play-off tie with either Real Madrid or fellow European heavyweights Inter.
Atleti placed 14th and well inside the play-off positions, so Diego Simeone's men will take on either Club Brugge or Galatasaray.
Alex Baena was denied the opener after VAR spotted he was offside when sweeping home, and Julian Alvarez saw a goal straight from a corner forced to be re-taken, with Sorloth meeting David Hancko's cross with an emphatic header between those incidents to have Atleti ahead.
But Bodo were level when Fredrik Bjorkan found Sjovold down the right, and the full-back drilled his shot past Jan Oblak.
Alvarez missed a gilt-edged chance, and Pablo Barrios smashed the bar as Atleti sought to re-take the lead, but Hogh got the final touch from a scramble in Atleti's area to put the underdogs ahead.
Sorloth and Barrios both had further chances, yet it was Bodo – who earned another memorable win at home to Manchester City last week – who earned the wonderful result they needed.
Data Debrief: Knutsen Joins Famous Quintet In Guardiola And Simeone Club
Bodo boss Kjetil Knutsen finds himself in glorious company. By beating City and Atleti in consecutive games, he joins Jurgen Klopp, Carlo Ancelotti, Luis Enrique, Thomas Tuchel and Bruno Genesio as one of six managers to own a Champions League win over Pep Guardiola and Simeone.
They are the first Norwegian side to progress from the group/league phase of a campaign since Rosenborg in 1996-97 (who reached the quarter-finals).
Hogh has scored with three of his last six shots on target in the competition (two vs Man City, one vs Atleti), after he did not score with any of his first 16 shots in the tournament this season (including two penalties).
It was a night for Atleti to forget, but Sorloth did become the first Norwegian player to score a European Cup/Champions League goal against a Norwegian opponent.
And Koke made his 110th Champions League appearance for Atleti under Simeone. It is the third-most games by a player under one manager in the competition, after Ryan Giggs (134) and Paul Scholes (124) for Alex Ferguson's Manchester United.
