The Brazilian combined to great effect with Philippe Coutinho (left) and Adam Lallana (right) in attack, with some sumptuous one-touch play exploiting an off-colour City back line, featuring a surprise centre-back pairing of Eliaquim Mangala and Martin Demichelis.
The off-ball work of Firmino, Coutinho and Lallana will have buoyed a frantic Klopp on the touchline, with the trio pressing high throughout.
With Lucas Leiva patrolling at the base of midfield, Liverpool were given license to overwhelm in the final third.
At left-back, Alberto Moreno remained solid in defence and consistent in supporting attacks, while Nathaniel Clyne was more reserved on the opposite flank, looking to cover for Martin Skrtel at centre-back.
With Firmino and Coutinho both withdrawn in the second half, and Jordon Ibe and Christian Benteke taking their place, Klopp’s system shifted slightly.
While Benteke was instructed to run the channels, the Belgian dropped deeper than Firmino in his 13 minutes on the field.
Ibe was unable to influence play as strongly as Coutinho, but his pace and confidence on the ball created Liverpool some promising openings towards the end of the second half.
As the final whistle was blown at the Etihad, however, the intensive, three-pronged attack of Firmino, Coutinho and Lallana proved the difference for Klopp.
With Firmino shining in a central role, Klopp now faces a selection headache.
Both Sturridge and Benteke will be itching to start at home to Bordeaux on Thursday night, but will the German alter a successful system?