After Manchester City moved to the summit with a hard-fought triumph of its own against Tottenham Hotspur just over 24 hours earlier, the Reds were made to sweat in the April sunshine by a side occupying the final relegation spot in the table.
Eventually, Liverpool found a clever way to break down a stubborn Cardiff defence, Georginio Wijnaldum meeting Trent Alexander-Arnold's corner with a powerful first-time finish.
A foul on Mohamed Salah by Sean Morrison allowed James Milner to wrap up a ninth successive win in all competitions for Jurgen Klopp's side from the penalty spot, meaning it now sits two points clear of the reigning champion, which has a game in hand.
After booking its place in the UEFA Champions League semi-finals in midweek, Liverpool returned to domestic duties knowing only a victory would suffice in the Welsh capital.
Roberto Firmino carelessly lifted their best chance of the first half over the top, wasting good work by fellow forwards Salah and Sadio Mane as his left-footed shot cleared both the advancing Neil Etheridge and the crossbar.
Cardiff's goalkeeper was needed to make a close-range save to deny Salah shortly after, though Liverpool did not pick up the pace until after the interval, leading to Wijnaldum’s 57th-minute strike from a well-worked set piece.
Having wasted a free header with the score at 1-0, letting Alisson off the hook after the goalkeeper had failed to deal with a corner, Morrison was adjudged to have pulled down Salah in the other penalty area, allowing Milner, who replaced fellow substitute Fabinho because of a head injury, to put the result beyond doubt.
Pep Guardiola’sCity side can leapfrog Liverpool again with victory at Old Trafford on Thursday (AEST), putting it in pole position to retain the title with three games remaining. Astonishingly, Klopp’s squad could end up as the bridesmaid on 97 points.
Liverpool hosts relegated Huddersfield Town at Anfield next on Saturday (AEST).