LIAM Buchanan's late goal broke Stranraer hearts and ended their seven-game unbeaten run at Stair Park.
The game looked destined to finish 0-0 as time wore on but Buchanan popped up to grab a winner with six minutes left, despite the home side's appeals for offside.
Stevie Farrell made three changes from the side that picked up a point in a 1-1 draw with Queen's Park last weekend at Stair Park.
Michael Donald was missing through injury while David Barron and Kyle Turner both dropped to the bench.
That meant a start for David Wilson, who impressed against the Spiders after replacing Donald, while Liam Dick returned from suspension and Mark McGuigan also earned a recall.
Livingston, flying high at the top of the league and looking for an immediate return to the Championship, had lost last time out to East Fife and were looking to get back to winning ways.
It was the Lions who were first to test a goalkeeper when Stranraer were caught up field in the opening five minutes.
The impressive Josh Mullin raced clear down the right and attempted to cut the ball back for Nikolay Todorov, only for Cameron Belford to block with his legs.
At the other end, Stranraer called Liam Kelly into action midway through the first half.
Scott Agnew and Craig Malcolm exchanged passes but Agnew's shot was gathered by the goalkeeper at the second attempt.
Agnew had a volley blocked just before the half hour mark before Belford did well to claw Scott Pittman's bouncing shot to safety just before the break.
Stranraer were looking reasonably comfortable at the back without really testing Kelly at the other end but they were thankful Craig Halkett's aim was off just before the hour mark.
Mullin's corner was perfect for the central defender but he planted his header well beyond the left post.
Scott Robertson and Malcolm both forced efforts on target but it looked like the spoils would be shared until six minutes from time.
Substitute Nicky Cadden's mishit shot was collected by Buchanan, who had the reactions to bring it under control and fire towards goal.
Belford blocked the shot but it fell straight back to the striker who made no mistake at the second time of asking.
It was a blow which came too late for Stranraer to really recover from, with Craig Pettigrew's ambitious volley on the turn in stoppage time about the best they could muster.
The late goal ultimately proved decisive in a game where both sides would likely have been content with - and merited - a point.
Now, the Blues have to pick themselves up for the long trip north to Peterhead and another vital game in the bid to beat the drop.
Stranraer: Belford, Robertson, Dick, Bell, Pettigrew, Wilson (Turner 64), Thomson, Agnew, McGuigan (Kassarate 70), Gibson, Malcolm (Kemp 85).
Not used: Barron, McGowan, Morena and Currie.
Livingston: Kelly, Longridge, Lithgow, Gallagher, Halkett, Mullin, Todorov (Cadden 62), Pittman, Millar, Buchanan (Sampson 89), Mullen (Crighton 82).
Not used: Ogilvie, Knox, Sinclair and Maley.
Referee: Craig Napier