The former forward was also full of praise for their implementation of Jurgen Klopp's pressing game.
The Reds put in a highly established performance at the Etihad on Saturday evening, as they ran out 4-1 winners.
Their attacking display was particularly impressive, with Lallana, Coutinho and Firmino proving a thorn in the City defence throughout.
The trio created a number of chances, with Joe Hart in fine form to keep the number of goals he conceded to just four, denying Firmino on multiple occasions.
And Shearer was full of praise for the trio for their display in the win.
“It was almost a perfect performance,” he told Match of the Day.
“They were absolutely outstanding. The front three of Lallana, Coutinho and Firmino caused them problems for the vast majority of the game. City couldn’t handle them.”
The former forward was also full of praise for Liverpool’s pressing in the game.
Much was made of Jurgen Klopp’s infamous Geggenpressing style from his Borussia Dortmund days, with many expecting him to implement it at Anfield.
That is something he has done, with the aforementioned front three constantly pressing the City defence to great effect.
And Shearer says that aspect was what impressed him most from their win.
“What impressed me most is the way they pressed the ball,” he added.
“Not only were they high, but they were patient when City had the ball in the final third as well.”