Michael Gardyne's double edged Ross County to within a point of fourth place in a five-goal thriller.
The home side capitalised on a fast start when Craig Curran tapped home before Tope Obadeyi equalised with Kilmarnock's first effort on target.
Josh Magennis knocked home a corner straight after half-time before Gardyne took control with two fabulous finishes across Jamie Macdonald.
Defeat leaves Gary Locke's side in the relegation play-off place.
Jim McIntyre's side began with real attacking intent, creating chance after chance in the opening minutes.
Gardyne, Jonathan Franks and Liam Boyce all threatened early on, and the opener duly arrived when Jackson Irvine drove forward and picked his moment beautifully to release Gardyne in behind.
The winger measured a low ball across the six-yard box which Curran tapped home easily despite Kilmarnock goalkeeper Jamie MacDonald's efforts.
It was well worked by the home side but at this level you expect better defending.
Obadeyi was first to threaten for Kilmarnock as he kept going despite being fouled, but his shot was wide of goal.
To their credit, Kilmarnock managed to stem the tide and chances became infrequent. You began to wonder if a failure to press home that early dominance might end up costly.
It did. Obadeyi chased a ball across goal, gathered, evaded Jamie Reckord and drilled in a low shot to the astonishment of the home crowd.
If County wondered how they were only level at half-time they were immediately considering how they were behind right at the start of the second period.
A well-worked corner saw Magennis lose his marker at the front post and he touched home just inside the post.
However, McIntyre's side are nothing if not resilient as they proved in the 5-2 win over Dundee.
A superb ball from Irvine out wide released Gardyne who seemed on form all night and he drilled a low effort across Macdonald for a prompt equaliser.
Magennis was upended by Boyd giving Craig Slater a free hit, but he misjudged the bend and curl and it sailed over.
Gardyne's influence was to prove decisive as he gathered on the left again and jinked brilliantly before sending another shot across Macdonald into the far corner. It was a man of the match performance.
Irvine then drove forward again and released Boyce on the left, but his shot was weak and saved by Macdonald
Incredibly Kilmarnock should have squared it once more when Obadeyi had a header from eight yards after a wonderful ball from Magennis.
Boyce's fierce drive was well saved by Macdonald before substitute Kris Boyd headed narrowly over right at the death but County held out for a valuable win.
Kilmarnock must hope results elsewhere go in their favour having played two, or in some cases three more games than sides immediately above them with Dundee United now having the opportunity to close in with two games in hand.
Full Time Match ends, Ross County 3, Kilmarnock 2.
90:00 +5:02 Full timeFull Time Second Half ends, Ross County 3, Kilmarnock 2.
90:00 +4:00Stewart Murdoch (Ross County) wins a free kick in the defensive half.
90:00 +3:57Foul by Dale Carrick (Kilmarnock).
90:00 +3:12Attempt missed. Conrad Balatoni (Kilmarnock) header from the centre of the box is just a bit too high following a corner.
90:00 +2:40Corner, Kilmarnock. Conceded by Jackson Irvine.
90:00 +2:09Corner, Kilmarnock. Conceded by Jackson Irvine.
90:00 +1:40Foul by Jackson Irvine (Ross County).
90:00 +1:40Steven Smith (Kilmarnock) wins a free kick on the left wing.
87:51Hand ball by David Syme (Kilmarnock).
87:03 SubstitutionSubstitution Substitution, Ross County. Brian Graham replaces Liam Boyce.
83:47 SubstitutionSubstitution Substitution, Kilmarnock. Dale Carrick replaces Adam Frizzell.
81:23Attempt saved. Liam Boyce (Ross County) right footed shot from the centre of the box is saved in the bottom right corner.
80:38Corner, Ross County. Conceded by Stuart Findlay.
79:08Michael Gardyne (Ross County) wins a free kick in the defensive half.
79:08Foul by David Syme (Kilmarnock).
77:38Corner, Ross County. Conceded by Tope Obadeyi.
76:01Jackson Irvine (Ross County) wins a free kick in the attacking half.
76:01Foul by Steven Smith (Kilmarnock).
74:00Stuart Findlay (Kilmarnock) wins a free kick in the defensive half.
Foul by Craig Curran (Ross County).
72:52 BookingBooking Kevin McHattie (Kilmarnock) is shown the yellow card for a bad foul.
72:45Craig Curran (Ross County) wins a free kick on the right wing.
72:45Foul by Kevin McHattie (Kilmarnock).
71:20Corner, Ross County. Conceded by Conrad Balatoni.
70:34 SubstitutionSubstitution Substitution, Ross County. Rocco Quinn replaces Jonathan Franks.
69:56 SubstitutionSubstitution Substitution, Kilmarnock. Kris Boyd replaces Greg Kiltie.
69:35Jamie Reckord (Ross County) wins a free kick in the defensive half.
69:35Foul by Tope Obadeyi (Kilmarnock).
68:51Attempt saved. Andrew Davies (Ross County) header from the centre of the box is saved in the centre of the goal.
68:21Jonathan Franks (Ross County) wins a free kick in the defensive half.
68:21Foul by Stuart Findlay (Kilmarnock).
65:55 SubstitutionSubstitution Substitution, Ross County. Stewart Murdoch replaces Martin Woods because of an injury.
65:33Attempt missed. Tope Obadeyi (Kilmarnock) header from the centre of the box is close, but misses to the left.
61:38Corner, Ross County. Conceded by Jamie MacDonald.
61:05Attempt saved. Liam Boyce (Ross County) right footed shot from the centre of the box is saved in the bottom left corner.
58:57 SubstitutionSubstitution Substitution, Kilmarnock. David Syme replaces Mark O'Hara.
58:20Attempt missed. Craig Slater (Kilmarnock) right footed shot from outside the box is too high.
55:58 Goal scoredGoal! Goal! Ross County 3, Kilmarnock 2. Michael Gardyne (Ross County) left footed shot from the left side of the box to the bottom right corner. Assisted by Liam Boyce.
54:00Foul by Martin Woods (Ross County).
54:00Craig Slater (Kilmarnock) wins a free kick in the defensive half.
53:26Attempt missed. Craig Slater (Kilmarnock) right footed shot from outside the box is just a bit too high from a direct free kick.
52:50 BookingBooking Scott Boyd (Ross County) is shown the yellow card for a bad foul.
52:43Foul by Scott Boyd (Ross County).
52:43Josh Magennis (Kilmarnock) wins a free kick in the attacking half.
51:16Martin Woods (Ross County) wins a free kick in the attacking half.
51:16Foul by Steven Smith (Kilmarnock).
49:57 Goal scoredGoal! Goal! Ross County 2, Kilmarnock 2. Michael Gardyne (Ross County) left footed shot from the left side of the box to the bottom right corner. Assisted by Jackson Irvine.
49:03Foul by Andrew Davies (Ross County).
49:03Adam Frizzell (Kilmarnock) wins a free kick in the defensive half.
47:13 Goal scoredGoal! Goal! Ross County 1, Kilmarnock 2. Josh Magennis (Kilmarnock) left footed shot from the centre of the box to the bottom left corner. Assisted by Steven Smith with a cross following a corner.
46:54Corner, Kilmarnock. Conceded by Andrew Davies.
45:49Foul by Scott Boyd (Ross County).
45:49Josh Magennis (Kilmarnock) wins a free kick in the attacking half.
45:00Second Half begins Ross County 1, Kilmarnock 1.
45:00 +0:13 Half timeHalf Time First Half ends, Ross County 1, Kilmarnock 1.
40:54Foul by Andrew Davies (Ross County).
40:54Josh Magennis (Kilmarnock) wins a free kick in the attacking half.
40:27Corner, Ross County. Conceded by Craig Slater.
39:49Jamie Reckord (Ross County) wins a free kick on the left wing.
39:49Foul by Tope Obadeyi (Kilmarnock).
38:31Attempt missed. Craig Slater (Kilmarnock) right footed shot from outside the box is too high.
37:22Attempt missed. Adam Frizzell (Kilmarnock) left footed shot from the left side of the box is close, but misses to the left.
35:19Foul by Jackson Irvine (Ross County).
35:19Steven Smith (Kilmarnock) wins a free kick in the attacking half.
33:20Foul by Richard Foster (Ross County).
33:20Adam Frizzell (Kilmarnock) wins a free kick in the defensive half.
32:06 Goal scoredGoal! Goal! Ross County 1, Kilmarnock 1. Tope Obadeyi (Kilmarnock) left footed shot from the right side of the box to the bottom right corner. Assisted by Josh Magennis.
25:49Corner, Ross County. Conceded by Stuart Findlay.
25:12Attempt missed. Tope Obadeyi (Kilmarnock) right footed shot from long range on the right is close, but misses to the right.
23:21Foul by Scott Boyd (Ross County).
23:21Adam Frizzell (Kilmarnock) wins a free kick in the attacking half.
20:00Craig Curran (Ross County) wins a free kick on the right wing.
19:57Foul by Kevin McHattie (Kilmarnock).
19:35Michael Gardyne (Ross County) wins a free kick in the attacking half.
19:35Foul by Tope Obadeyi (Kilmarnock).
18:37Andrew Davies (Ross County) wins a free kick in the attacking half.
18:37Foul by Josh Magennis (Kilmarnock).
16:16Attempt missed. Martin Woods (Ross County) left footed shot from the left side of the box is close, but misses to the left.
11:42 Goal scoredGoal! Goal! Ross County 1, Kilmarnock 0. Craig Curran (Ross County) right footed shot from very close range to the centre of the goal. Assisted by Michael Gardyne.
9:16Andrew Davies (Ross County) wins a free kick in the attacking half.
9:16Foul by Craig Slater (Kilmarnock).
6:13Attempt saved. Craig Curran (Ross County) left footed shot from the left side of the box is saved in the centre of the goal.
5:13Foul by Martin Woods (Ross County).
5:13Greg Kiltie (Kilmarnock) wins a free kick on the right wing.
4:14Attempt missed. Liam Boyce (Ross County) right footed shot from the centre of the box is close, but misses to the right.
3:16Attempt missed. Jamie Reckord (Ross County) left footed shot from outside the box misses to the left.
2:43Corner, Ross County. Conceded by Kevin McHattie.
1:10Attempt missed. Andrew Davies (Ross County) header from the centre of the box misses to the left following a corner.
1:00Corner, Ross County. Conceded by Stuart Findlay.
0:41Attempt blocked. Michael Gardyne (Ross County) right footed shot from the centre of the box is blocked.
0:21Foul by Craig Slater (Kilmarnock).
0:21Michael Gardyne (Ross County) wins a free kick in the attacking half.
0:00First Half begins.
0:00Lineups are announced and players are warming up.
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