Second-half goals from Kris Boyd and
sub Allan Johnston increased the pressure on
relegation-threatened Livingston.
Boyd's 18th of the season in the 75th minute and Johnston's strike 10
minutes later, consigned the Lions to defeat.
Livi must now avoid defeat against Dundee next week to be sure of
preserving their top-flight position.
However, they were dealt another blow in the second period when
defender David McNamee was carried off with an ankle injury.
Livi also went into the game on the back of two successive wins and
after collecting 10 points out of a possible last 12 with just two SPL
defeats since February - at the hands of Celtic and Hearts.
But their fine run was derailed by Jim Jefferies' in-form Kilmarnock,
who moved into seventh spot with the win.
It took eight minutes for any kind of goalmouth action to develop,
but Gabor Vincze's excellent right-wing cross was flapped away by Killie
keeper Alan Combe for a corner.
From Burton O'Brien's delivery Combe was again dubious under pressure
and Colin McMenamin turned the resulting loose ball into the net - only
for referee Iain Brines to rule it out for a foul on the keeper.
Peter Leven's cross-shot on 15 was Killie's first real foray into
Livi territory and, a minute later Gary Wales, who along with Garry Hay,
signed a new deal before the game, played Gary McDonald in through the
inside left berth.
Livi keeper Roddy McKenzie had to be sharp to smother the
midfielder's effort.
Kris Boyd, back up front after a game on the bench against Dundee
United, looked lethargic in the early stages, but went close with a
snap-shot on 36 which flashed just wide.
The second half started as the first had ended and it took 13 minutes
before either side threatened to break the deadlock.

Killie were looking the more dangerous, with Boyd in particular a
threat and, after 67 minutes, the striker curled a fine effort just
wide.
Moments later, David McNamee was carried off on a stretcher after
appearing to catch his studs in the turf.
Killie took the lead their second-half play merited on 75 when
substitute Murray's cross was volleyed towards goal by
Gary Wales and Kris
Boyd was there to add the finishing touch,
to net his 18th goal of the season.
Steven Naismith was replaced by Allan
Johnston on 85 and the former Rangers and Hearts winger made the
game safe with his second touch.
His first was when he controlled an intelligent knock-down from Wales
before drilling the ball beyond McKenzie with his right foot.
Johnston, whose only two previous SPL goals this term coincidentally
came against Livi, nearly made it 3-0 three minutes later, but his shot
was deflected wide.
Kilmarnock: Combe, Fowler, Lilley, Hay,
Greer, Locke, McDonald,
(Dodds 22mins), Leven
(Murray 69 mins), Naismith (Johnston 84 mins),
Wales, Boyd
Subs: Smith, Nish, Hamill Campbell
Attendance: 4,184
None