Chris Erskine's goal was enough to earn Livingston their first victory since mid-December at the expense of a Kilmarnock side who have not won in their last seven matches.
The former Partick forward scored in the final minute of the first half to end a barren run of nine matches without a win for Gary Holt's side.
Kilmarnock, whose early season form has tailed off dramatically, hit the crossbar three times but could not find an equaliser.
Livingston made four changes from the side that had lost at home to Dundee the previous weekend. In came Steven Lawson, Craig Sibbald, Steven Lawless and Erskine for Hakeem Odoffin, Scott Robinson, Ryan Hardie – who all dropped to the bench – and the suspended Shaun Byrne.
Kilmarnock, in turn, made seven changes from the team beaten by Rangers in midweek, although were able to call upon Daniel Bachmann after the goalkeeper won his appeal against the red card he had received in the defeat at Ibrox. There was also a first league appearance of the season for left-back Calum Waters.
A tame first half had yielded only two chances of note prior to Erskine's goal and both went the way of the visitors.
Waters' cross after 18 minutes was perfectly placed for Kris Boyd only for the veteran striker's header to strike the top of the crossbar and bounce over for a goal kick.
It took another 20 minutes for one of the goalkeepers to be finally called into action, Rory McKenzie venturing forward from midfield before hitting a shot that Liam Kelly pushed away from goal.
It was Livingston, though, who made the breakthrough a minute before the break with their first attempt on target.
It stemmed from a long throw-in by Alan Lithgow, flicked on by Lawless for his former Partick team-mate Erskine. The forward turned Scott Boyd before finishing smartly past Bachmann.
Kilmarnock responded early in the second half with a long-range shot from Eamonn Brophy that struck the top of the crossbar before Livingston enjoyed a period of dominance.
Lawson had a driven effort well saved by Bachmann before a weak punched clearance from the goalkeeper fell to Sibbald whose shot was blocked by the diligent Waters.
Kilmarnock then struck the woodwork again. Brophy's 25-yard free-kick was pushed away by Kelly into the path of McKenzie who crashed his shot against the crossbar from a tight angle.