The 34-year-old pounced on a fumbled clearance by Wes Morgan to stroke in the winner for the Reds after Adam Lallana cancelled out a Simon Mignolet own goal opener
The hosts took the lead on 22 minutes when Leonardo Ulloa's shot found the back of the net via the post and the back of Simon Mignolet, but Adam Lallana pounced to bring the visitors level four minutes later.
And amid speculation over whether he will sign a new contract at Anfield, Gerrard slotted in from a more advanced midfield role on 54 minutes after a fumbled clearance from Wes Morgan, who later received a straight red card when he hauled down Rickie Lambert as the last man.
And Jordan Henderson converted from close range after a mistake from Leicester keeper Kasper Schmeichel and a superb backheel from the outstanding Raheem Sterling with seven minutes to go to ensure Liverpool made it back-to-back top-flight wins for only the second time this season.
Leicester manager Nigel Pearson named an unchanged XI, while Gerrard returned alongside Javier Manquillo and Lallana for Liverpool.
Schmeichel's opposite number Mignolet was almost left red faced in the 19th minute when he inexplicably cleared straight to Esteban Cambiasso but the veteran Argentine midfielder side-footed wide of an open goal from 30 yards.
Mignolet looked to have atoned for the misjudgement when he saved sharply from Jamie Vardy but Ulloa kept possession alive and his resulting shot struck the near post and cannoned in via the prone goalkeeper.
Liverpool responded immediately, though, and equalised four minutes after going behind - Lallana reacting quickest to drill a low shot past Schmeichel when Morgan failed to head clear under pressure from Lambert.
Alberto Moreno replaced Manquillo for the second-half, allowing Liverpool's weekend match-winner Glen Johnson to revert to his customary position of right-back.
Leicester pinned Liverpool back having won a pair of corners inside the opening minute of the second half but another botched clearance from the hapless Morgan saw the visitors go in front.
The centre-back stretched to divert Sterling's cutback away from goal but he could only place the ball into the path of Gerrard, who clinically steered home side-footed.
Ulloa blasted off target as Leicester looked to hit back, but Morgan's miserable evening was complete in the 63rd minute when he scuffed a backpass and responded by hauling down Lambert when through on goal to earn his marching orders.
Gerrard was unfortunate not to win a penalty when Schmeichel appeared to bring him down in the box soon after only for referee Lee Mason to wave his appeals away.
But Liverpool's nerves were eased when Schmeichel failed to deal with a low Gerrard cross and Sterling teed up Henderson to mark his 150th appearance for the club with a simple finish.