Playing at Glimt's home ground, Pep Guardiola's side dominated possession during the opening exchanges but were repeatedly exposed by sharp counter-attacks.

City created early openings, with Rayan Cherki missing a presentable chance and Erling Haaland curling narrowly wide, while Nico O'Reilly failed to convert a headed opportunity. Those misses proved costly.

Bodo/Glimt struck twice in the first half through Kasper Hogh, both goals created by Ole Blomberg. The opener came after Blomberg recovered from an Abdukodir Khusanov challenge before delivering a cross that Hogh finished clinically.

The second followed a mistake from Max Alleyne, allowing Jens Hauge and Blomberg to combine and tee up Hogh for his second of the night, giving the hosts a 2-0 lead at the break.

City, captained by Rodri, were grateful to goalkeeper Gianluigi Donnarumma, who made several important saves, including denying Hogh a hat-trick and keeping out Hakon Evjen.

However, just before the hour mark, Rodri surrendered possession and Glimt capitalised, with Hauge firing into the top corner to make it 3-0.

Cherki briefly offered hope with a deflected strike, assisted by O'Reilly, but moments later Rodri was sent off after receiving two yellow cards in quick succession.

Glimt struck the crossbar and had another goal disallowed, leaving City fortunate not to concede further.

"It's a difficult situation. We lose a ball and made a transition and they are fast. Sometimes you react. I don't know if the second one is a bit soft but it is what it is," said Pep Guardiola.

"At the moment, 3-1 and then [the red card] after one minute, everything is a little against for many things. When we started on New Year's Day in Sunderland we miss what we miss and after we started to get injuries and injuries and Matheus [Nunes] has flu.

"Many things are against us and in that level in the Champions League or against United it is more difficult to have that consistency that we had for one or two months where we were winning games and being there.

"Now, because we lost important players we lost a little bit but in general the tone of the team was much better than the last one. We had important players back home that could not give consistency to the team.

"They were a little fragile like last season in certain periods but how they fought 10 against 11 and a lot of players made a step up.

"We have to change the dynamic quick against Wolves and then Galatasaray and we are waiting for players to come back step by step."

Man Utd duo Victor Lindelof and Lisandro Martinez sidelined for at least a month