Hearts moved five points clear in third place in the Scottish Premiership as they piled the misery on Livingston, who have now lost 11 of their last 13 games.
Lawrence Shankland scored for a sixth consecutive game to secure the win, but only after missing a second-half penalty chance to break the deadlock.
Kenneth Vargas had given Hearts the lead two minutes after Shankland's miss and, while Andrew Shinnie's penalty did give Livingston hope, they were unable to find a leveller.
It was a tough day for David Martindale's side, who had Kurtis Guthrie's early header disallowed for offside, and they remain six points adrift at the bottom.
Livingston have been in woeful form - picking up two points from a possible 36 before this - but Hearts rarely enjoy trips to West Lothian.
It looked like that trend was set to continue as Zander Clark was forced into an early save from Ayo Obileye's powerful header.
The next headed effort left Clark motionless. Shinnie whipped in a cross from the left and Guthrie flicked his header brilliantly inside the back post. After a three-minute delay, VAR ruled out for offside.
That gave Hearts a jolt, and they responded when Shankland got on the end of a Peter Haring cross, looping the ball onto the face of the crossbar.
After the break, the visitors were gifted an opportunity from the spot when Alan Forrest was wiped out by Mikey Devlin. Shankland stepped up, but as in the Edinburgh derby, he missed, with his shot down the middle saved by Jack Hamilton.
The striker looked relieved when Vargas scored with the next attack. Forrest slid the ball through for the Costa Rican, who opened his body up and slotted under the keeper.
Shankland made mistake 10 minutes later. Receiving the ball from Forrest on the edge of the box, he delayed his shot before curling with the outside of his right foot into the bottom corner.
Livingston brought on Joel Nouble and new signing Tete Yengi - both standing well above six foot. The hosts launched balls into the box and won a penalty when Frankie Kent handballed.
Shinnie slotted the penalty down the middle - Livingston's first goal at home since October - but they would not go too close again.
The former Livingston winger impressed on his return, setting up both Hearts goals and running in behind well.
The Tony Macaroni Arena is not Hearts fans' favourite place to go. Before today, they'd only won there once since Livingston's promotion in 2018 and the scars of the 5-0 loss that year remain.
After the Livingston goal, the nerves started to fray. Crosses were catapulted into the Hearts box, with the giants of the Livi front line casting a shadow over the visiting defence.
Despite that, Hearts continued to foul their hosts in crossable territory, but ultimately they held on for a seventh away win of the season - four more than they had in the entirety of last season, and three more than they've had at home.
Livingston weren't far away from earning a point, but you have to think that if this was any other manager, at any other club, they would be out the door.
Martindale's side have picked up two points since 21 October, and appear to be careering toward relegation, but the manager is trusted to fix this problem in January. If anyone can do it at this club, it's probably him.
The winter break sets in, before Livingston host Raith in the fourth round of the Scottish Cup on 20 January (15:00), while Hearts visit Spartans the same day (12.15 GMT) live on the BBC Scotland channel.