The Reds faced arguably their biggest match of the season, travelling to a Foxes side full of confidence under Brendan Rodgers.
Substitute James Milner made it 2-0 with his first touch, stroking home from the penalty spot, before Firmino bagged his second.
Alexander-Arnold completed a magical performance with an inch-perfect finish from distance, as Liverpool went 13 points clear at the top of the Premier League.
Alexander-Arnold (9.6) was the undisputed Man of the Match, as he put in one of the best individual showings of the Klopp era.
The youngster was unplayable down the right flank and his end product was world class, whether providing or scoring.
TIA’s Henry Jackson gave Alexander-Arnold a perfect 10-out-of-10 rating, describing his display as “truly exceptional.”
The same applied with Ian Doyle of the Echo, who summed up the right-back by saying, “what a player.”
Firmino (9.1) was next in the average ratings, as he carried on his goalscoring form from the Club World Cup.
The Brazilian has now found the net in his last three appearances, with The Redmen TV claiming he is “on fire at the moment.”
Aside from his goalscoring heroics, FotMob highlighted Firmino’s off-the-ball work, pointing out that he made five ball recoveries and won four duels.
Jackson felt Henderson “bossed the midfield more than anyone,” while Squawka believe his “range of passing knows no bounds right now.”
Keita oozed class throughout the evening and Doyle gushed over his creativity in midfield, as he again took another step forward in his Liverpool career.
Alisson (6.8) earned the lowest rating on the night—the fact that he was untested and did nothing wrong sums up the Reds’ brilliance.