Second-half goals from Takumi Minamino and Divock Origi secured Liverpool's place in the Carabao Cup quarter-finals at the expense of a resolute Preston North End side at Deepdale.
Japan striker Minamino, who scored twice in his side's 3-0 win over Norwich City in the previous round, finished neatly from Neco Williams' cross to end the Championship outfit's stubborn resistance after 62 minutes.
Origi, who also netted in the previous round, then produced a brilliant improvised finish with his heel to put the result beyond doubt with six minutes remaining.
Jurgen Klopp named an entirely different Liverpool side to the one which thrashed Manchester United 5-0 on Sunday and despite dominating possession for long periods it was Preston who fashioned the best first-half opportunities.
Preston started cautiously as they sought to produce a huge upset and reach the first league cup quarter-final in their history but they eventually carved out some chances, the best of which came after 28 minutes.
In a remarkable goalmouth scramble, Liverpool goalkeeper Adrian produced a superb save to deny Sean Maguire and then Ryan Ledson's goal-bound follow-up was blocked by Williams and Brad Potts blazed over.
Tom Barkhuizen and Ledson had also both failed to find the target in good positions while Potts was unable to lift his shot over Adrian as Frankie McAvoy's side threatened on the break.
A flat and generally disjointed Liverpool team - perhaps hardly surprising given the changes - failed to register a shot on target prior to the interval and struggled to ignite after the break too.
Jurgen Klopp then brought on right-back Conor Bradley and pushed Williams forward and the change had the desired effect.
Alex Oxlade-Chamberlain's off-target drive from the edge of the box was the closest the subdued visitors had gone before Minamino's opener.
Liverpool were able to see out the tie in comfort when Origi flicked home from close range with a wonderful improvised finish after being set up by Williams as the Reds booked their place in the quarter-final draw, which takes place at 10:30 BST on Saturday, 30 October.