Jurgen Klopp's Reds worked hard for another one-goal win courtesy of Christian Benteke's second-half effort following their triumph over Leicester City on Boxing Day which also came via a sole Benteke goal.
The Belgian striker separated the two sides just 22 seconds into the second half when he raced onto a ball from Nathaniel Clyne, which was poked onwards by Adam Lallana, before slotting expertly beyond Vito Mannone to produce the fastest second half goal in the Premier League this season.
The Reds were unlucky not to be ahead during the opening 45 minutes but Roberto Firmino saw his rasping attempt from range tipped onto the upright by Mannone before the Italian keeper did well to deny the Brazilian's header from a Clyne cross.
Liverpool fought hard to retain their lead throughout the second half as Sunderland pressed for a leveller but were unable to break down the visiting defence, even when Mannone came forward to try and get a head on a late corner.
The victory sees Jurgen Klopp's Reds move up to seventh on the table having racked up 30 points in 19 outings as Sam Allardyce's Black Cats lost for the fifth straight time to remain second bottom and in deep trouble ahead of the New Year.
2015/16 PREMIER LEAGUE SEASON SCORES
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