Motherwell dropped from second to third in the Scottish Premier League after a decisive defeat by Ross County.
Ivan Sproule opened on 34 minutes, striking a Rocco Quinn pass under Motherwell keeper Darren Randolph.
Sproule should have doubled County's lead shortly after the re-start, but made amends by setting up Richard Brittain to score on 70 minutes.
The home side cemented the result in the final minute, Iain Vigurs volleying home from close range.
It was a five-star performance from County that saw the SPL debutants move into the top six for the first time. And the win also extend their unbeaten run to eight games, from which they have taken 20 points - more than half their current total of 38.
The first chance fell to Motherwell, but it was almost their only opportunity of the game when Michael Higdon's shot was blocked in the second minute. County replied when Sproule volleyed over before both Vigurs and Quinn tested keeper Darren Randolph.
The breakthrough came on 33 minutes when Vigurs supplied Sproule, who ran powerfully towards goal and slid the ball past Randolph.
Sam Morrow came close to County's second when he had a shot deflected past and, just before half-time, Adam Cummins headed a free kick over the bar at the other end.
Early in the second half Chris Humphrey gave Mark Brown some rare action while it was Randolph to the rescue when he intervened to deny Sproule who had been set up after a run down the left wing by Paul Lawson.
The returning James McFadden came on for Motherwell just after the hour and cannoned a disappointing 22-yard free-kick against the wall.
County then proceeded to extend their lead when Brittain fired home Sproule's cross from the edge of the box.
This finally silenced a small but very noisy nucleus of Motherwell fans who had attracted the attention of two dozen police and stewards after half-a-dozen smoke bombs had filled the ground with pungent fumes.
Brittain next curled a free-kick narrowly by after Stefan Wolfarth had been body checked by McFadden and Vigurs prompted Randolph into another fine save.
However, Vigurs' next effort in the 89th minute was more successful when. From around eight yards, he smacked home a ball from the right to complete an emphatic victory.
Live Text Commentary
Full Time The referee brings the game to a close.90:00 +2:27
Adam Cummins has shot on goal from just outside the area which goes wide of the right-hand upright.89:45 Substitution
Substitution Andre Hainault comes on in place of Paul Lawson.89:14
Gary Glen gives away a free kick for an unfair challenge on Simon Ramsden. Simon Ramsden takes the direct free kick.88:06
Assist by Rocco Quinn.88:06 Goal scored
Goal! - Iain Vigurs - Ross Co 3 - 0 Motherwell A goal is scored by Iain Vigurs from inside the penalty area low into the middle of the goal. Ross County 3-0 Motherwell.83:06
Shaun Hutchinson fouled by Gary Glen, the ref awards a free kick. Shaun Hutchinson takes the free kick.81:30
Iain Vigurs takes a shot. Darren Randolph makes a save.80:31 Substitution
Substitution Omar Daley replaces Chris Humphrey.79:43
Free kick crossed right-footed by Richard Brittain from left wing.79:43 Booking
Booking Shaun Hutchinson booked for unsporting behaviour.79:36
Free kick awarded for an unfair challenge on Steffen Wohlfarth by Shaun Hutchinson.78:03 Substitution
Substitution Gary Glen on for Sam Morrow.78:03 Substitution
Substitution Ivan Sproule leaves the field to be replaced by Steffen Wohlfarth.75:19
Sam Morrow has a headed effort at goal from close in which goes wide left of the goal.73:22
Nicky Law delivers the ball, Shaun Hutchinson takes a shot. Save by Mark Brown.73:22 Booking
Booking Booking for Richard Brittain for unsporting behaviour.73:14
James McFadden fouled by Richard Brittain, the ref awards a free kick.72:13 Substitution
Substitution (Motherwell) makes a substitution, with Robert McHugh coming on for Zaine Francis-Angol.72:13
Unfair challenge on Rocco Quinn by Nicky Law results in a free kick. Direct free kick taken by Grant Munro.
Assist on the goal came from Ivan Sproule.70:31 Goal scored
Goal! - Richard Brittain - Ross Co 2 - 0 Motherwell A goal is scored by Richard Brittain from the edge of the penalty box to the bottom left corner of the goal. Ross County 2-0 Motherwell.69:48
Nicky Law has an effort at goal from outside the box which goes wide right of the goal.67:37
James McFadden fouled by Paul Lawson, the ref awards a free kick. James McFadden produces a strike on goal direct from the free kick, Sam Morrow gets a block in.64:02
Free kick awarded for a foul by Scott Boyd on Adam Cummins. Free kick taken by Darren Randolph.63:13 Substitution
Substitution Stewart Carswell leaves the field to be replaced by James McFadden.63:13
Free kick awarded for an unfair challenge on Iain Vigurs by Michael Higdon. Free kick taken by Richard Brittain.61:27
Free kick crossed right-footed by Nicky Law from right wing, Scott Boyd makes a clearance.61:27 Booking
Booking Evangelos Ikonomou receives a caution.61:24
Unfair challenge on Keith Lasley by Evangelos Ikonomou results in a free kick.60:09
Free kick taken by Scott Boyd.60:09 Booking
Booking The referee shows Simon Ramsden a yellow card.60:00
Free kick awarded for an unfair challenge on Iain Vigurs by Simon Ramsden.57:51
Rocco Quinn concedes a free kick for a foul on Nicky Law. Nicky Law crosses the ball from the free kick right-footed from left channel, clearance made by Grant Munro.53:02
Inswinging corner taken right-footed by Richard Brittain.52:00
Effort from the edge of the box by Ivan Sproule goes wide of the right-hand upright.51:10
Mihael Kovacevic has an effort at goal from outside the area missing to the wide right of the goal.50:47
Ivan Sproule takes a shot. Save by Darren Randolph.49:44
Iain Vigurs fouled by Keith Lasley, the ref awards a free kick. The free kick is delivered right-footed by Richard Brittain from left channel, clearance made by Henrik Ojamaa.49:18
Foul by Henrik Ojamaa on Grant Munro, free kick awarded. Grant Munro restarts play with the free kick.48:08
Corner taken by Nicky Law, Mark Brown makes a save. Stewart Carswell gives away a free kick for an unfair challenge on Mark Brown. Mark Brown takes the direct free kick.46:46
Chris Humphrey takes a shot. Save by Mark Brown.45:01
The referee gets the second half underway.45:00 +0:04 Half time
Half Time The ref blows to signal half-time.44:10
Corner taken by Nicky Law from the right by-line, clearance by Paul Lawson.43:16
The referee blows for offside against Michael Higdon. Mark Brown takes the indirect free kick.40:57
Sam Morrow gives away a free kick for an unfair challenge on Keith Lasley. A cross is delivered by Nicky Law, Close range header by Shaun Hutchinson goes over the crossbar.39:50
Corner taken right-footed by Richard Brittain.38:23
Mihael Kovacevic fouled by Zaine Francis-Angol, the ref awards a free kick. Scott Boyd takes the direct free kick.33:38
Assist on the goal came from Sam Morrow.33:38 Goal scored
Goal! - Ivan Sproule - Ross Co 1 - 0 Motherwell Ivan Sproule grabs a goal from close range low into the middle of the goal. Ross County 1-0 Motherwell.29:12
Rocco Quinn takes a shot. Save by Darren Randolph.28:38
Free kick awarded for an unfair challenge on Sam Morrow by Stewart Carswell. Richard Brittain takes the direct free kick.27:58
The referee blows for offside against Ivan Sproule. Indirect free kick taken by Keith Lasley.26:23
Richard Brittain takes a shot. Blocked by Adam Cummins. Richard Brittain takes a short corner.23:00
Simon Ramsden challenges Iain Vigurs unfairly and gives away a free kick. Free kick crossed right-footed by Richard Brittain from left wing, save made by Darren Randolph.20:48
Effort on goal by Ivan Sproule from just inside the area clears the bar.18:20
Foul by Simon Ramsden on Iain Vigurs, free kick awarded. Scott Boyd takes the direct free kick.9:22
Rocco Quinn fouled by Keith Lasley, the ref awards a free kick. Free kick taken by Scott Boyd.3:56
Michael Higdon concedes a free kick for a foul on Paul Lawson. Richard Brittain restarts play with the free kick.1:27
Corner taken right-footed by Nicky Law from the right by-line, clearance by Richard Brittain.0:00
The referee gets the game started.
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