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.