The Premier League champions put in arguably their best performance of the season to beat the Foxes at Anfield in order to go joint-top of the table.
Firmino had scored just once before the win against Brendan Rodgers’ side and pressure has been building on the Brazilian, who is facing increased competition following the arrival of Diogo Jota.
The critics were out in full force midway through the second half when Firmino missed a one-on-one against Kasper Schmeichel and the night looked like ending as a frustrated one for the former Hoffenheim striker.
However, Firmino scored towards the end of the game when he headed in a James Milner corner and Klopp defended his striker after the win, hitting out at those lining up to criticise the Brazil international.
‘That front line didn’t play too often together but how they did that tonight was not bad,’ Klopp told DAZN.
‘Diogo is a smart player, Sadio put in an unbelievable shift.
‘Bobby, what people say about him is ridiculous. Just because you have nothing else to talk about sometimes is my feeling.
‘You cannot be closer to a goal than he was tonight. Everybody thought in that moment, “yes, great” and exactly the right goalscorer. He played outstanding again so all good.’
Liverpool without Mohamed Salah, Virgil van Dijk, Jordan Henderson and Trent Alexander-Arnold against Leicester but their replacements performed admirably.
Milner, playing at right-back, provided two assists while Jota became the first Liverpool player in history to score in his first four home games for the club.