Signs of ring rust were to be expected from Copenhagen, who were thrown in at the deep end after a two-month winter break from competitive action, and City sought to capitalise through a barrage of early opportunities.
Nathan Ake should have put the visitors in front with a volleyed rebound from point-blank range before Kevin De Bruyne avenged his teammate’s miss by latching onto Phil Foden’s reverse pass and nestling a composed finish into the far corner.
It was shaping up to be a case of how many for City until an injury to the unfortunate Jack Grealish, on his first start for over a month, marked a turning point for the hosts.
A rare mistake from Ederson created the equaliser, but there was still plenty to do for debutant Magnus Mattsson on the edge of the box as he confidently stroked his effort into the top corner.
The pendulum swing proved to be temporary, however, as City benefitted from their own moment of good fortune just before the break, with a tackle ricocheting into the path of Bernardo, whose dinked finish was as deft as fans have come to expect of the magical Portuguese.
For all of their possession, City’s clear-cut chances were limited by the Danes’ resolute defensive unit, as long-range shots from De Bruyne and Jeremy Doku were both dealt with by Kamil Grabara.
There was no need for either side to go for broke, with a second leg still to come, but the Sky Blues earned a valuable two-goal cushion at the death when Foden turned in De Bruyne’s cutback to leave Copenhagen deflated.
City did what they came to do at Parken Stadium on their quest to reach at least the UCL quarter-finals for a seventh successive campaign.
Copenhagen, meanwhile, will be up against it when they bid to make the last eight for the first time ever at the Etihad Stadium in three weeks’ time.
Flashscore Man of the Match: Kevin De Bruyne (Manchester City)
