Bernardo Silva, Kevin De Bruyne and Jeremy Doku were all on the scoresheet as the reigning Premier League champions celebrated a morale-boosting win and picked up their first three points since the end of October.
The Citizens' convincing victory at the Etihad Stadium was marred, however, as defensive duo Nathan Ake and Manuel Akanji were both forced off with injuries.
While Akanji was withdrawn at half time with an unspecified issue, Ake appeared to sustain a hamstring injury in the closing stages of the second half after challenging for the ball, and he gingerly walked down the tunnel after receiving treatment.
Ake has already been limited to just eight matches across all competitions after nursing a hamstring problem earlier in the season, and the Dutchman's fresh injury is now set to see him face another period on the sidelines.
Guardiola: 'Ake injury doesn't look good'
Speaking at his post-match press conference, a downbeat Pep Guardiola suggested that Ake is set to out for longer than Akanji, who has 'struggled a lot' over the last few months with his fitness.
"The problems continue with Manu and Nathan, but we prove what an incredible group of players we have at our disposal," said the Citizens boss.
"Nathan doesn't look good. We will see tomorrow. Manu has struggled a lot over the last two months. I can't thank them enough for the effort they do. We will see in three days what happens."
Guardiola added: "I'm sad for Nathan. Manu we'll see. Maybe not Selhurst Park (Crystal Palace fixture on Saturday) but Turin (Juventus fixture on December 11). Nathan I think will be [out for] longer."
Meanwhile, Guardiola has provided a positive update on Phil Foden, who was left out of Man City's matchday squad against Forest due to bronchitis.
Asked whether Foden could be out for weeks with his illness, Guardiola said: "Phil had bronchitis, so when he has no fever he will be ready."
How long could Ake be sidelined for with latest injury?
While both Akanji and Foden could be fit to play for Man City in Saturday's Premier League clash with Crystal Palace, Ake is almost certain to miss out and is not expected to be involved in the Citizens' upcoming fixtures leading up to Christmas.
Recovery from a hamstring injury can take days, weeks or even months depending on how severe it is. Ake is not thought to have completely torn his hamstring, which would take several months to heal, but pulling the muscle - which he has previously had issues with - could force him to spend weeks in the treatment room.
Ake has now emerged as a major doubt for Man City's next Champions League game away against Juventus on December 11, and also the Manchester derby against Ruben Amorim's Manchester United at the Etihad four days later.
Guardiola's side then travel to Aston Villa on December 21, before taking on Everton (Boxing Day) and Leicester City (December 29) in their final two Premier League fixtures of 2024.
Ake will now join Rodri (ACL), Oscar Bobb (leg fracture), John Stones (foot) and Mateo Kovacic (unspecified) on the sidelines, although the latter could be ready to return before Christmas.
Written by
Oliver Thomas