Ivan Sproule's second-half header brought Ross County a first win in almost 15 years over visitors Dundee United, who had Barry Douglas sent off.
Iain Vigurs and Steffen Wohlfarth had early chances for County while Jon Daly's header was close to giving United a half-time lead.
Sproule netted from Vigurs' cross and Douglas's red card for a foul on the goalscorer shortly after seemed harsh.
The crossbar denied Richard Brittain from doubling County's lead.
Sproule being in the right place at the right time to register his sixth goal for Ross County since he joined in January means his side are propelled up to fourth place in the Scottish Premier League.
With eyes on European football next season, they are now breathing down the necks of northern neighbours Inverness CT with a Highland derby still to play.
It was also the Northern Irishman's foot which was caught late by United's left-back Douglas in a second-half challenge that referee Kevin Clancy deemed worthy of a red card, when most at Victoria Park expected to see yellow.
The Tayside outfit remain in sixth position and this was their first defeat by County since two goals from their current manager Derek Adams put them to the sword in a League Cup tie in 1998.
On a poor surface, Vigurs had the hosts' early attempts on goal; firstly testing United goalkeeper Radoslaw Cierzniak with a low left-footed effort after Willo Flood's mis-control, then slicing wide from Sproule's centre.
Flood, taking longer to get up to speed than visiting manager Jackie McNamara would prefer, was caught in possession by County midfielder Paul Lawson, who in turn unleashed a searching pass through the middle for Sproule.
Cierzniak, though, rushed out to clear well.
Sproule capitalised on Flood's third error in quick succession to send a sweeping ball to Wohlfarth, but the Dingwall side's bustling German striker had his shot from 10 yards blocked by United defender Brian McLean.
Working out how to cope with Tangerines front-man Daly is a work in progress for defences around the country and his header from Douglas's free-kick would have found the bottom corner had it not been for Michael Fraser's diving save.
Lawson had already shown an aptitude for long-range passing and after the break he did so again, to great effect.
This time he found Vigurs on the left-hand side of United's box, who stole a yard on Sean Dillon in making for the bye-line and dinked a perfect cross to the back post for Sproule to nod into the net under pressure from Douglas.
The former Hibs striker had an eventful night, recovering from the foul that resulted in Douglas's dismissal to cut back the ball for another Vigurs half-chance.
Captain Brittain, top scorer for club so far in 2012-13, has been instrumental in a successful County side and his 25-yard strike was nearly his 11th goal of the season, but it thumped the crossbar.
Live Text Commentary
Full Time The referee signals the end of the game.90:00 +1:34
Free kick awarded for a foul by Sean Dillon on Iain Vigurs. Iain Vigurs takes the direct free kick.90:00 +1:00
Unfair challenge on Mihael Kovacevic by Jon Daly results in a free kick. Free kick taken by Richard Brittain.90:00 +0:05 Substitution
Substitution Martin Scott joins the action as a substitute, replacing Ivan Sproule.87:42
Corner from right by-line taken by Willo Flood.85:25
Corner taken short by Michael Gardyne.83:58
Effort on goal by Richard Brittain from inside the penalty area goes harmlessly over the bar.82:41
Willo Flood gives away a free kick for an unfair challenge on Stuart Kettlewell. Direct free kick taken by Richard Brittain.80:24
Radoslaw Cierzniak takes the indirect free kick.80:24 Substitution
Substitution Steffen Wohlfarth leaves the field to be replaced by Stuart Kettlewell.80:24
The assistant referee signals for offside against Steven Ross.79:49
Free kick awarded for a foul by Brian McLean on Ivan Sproule. Richard Brittain restarts play with the free kick.79:02
Paul Lawson takes a shot. Radoslaw Cierzniak makes a save.77:20 Substitution
Substitution Michael Gardyne replaces Gary Mackay-Steven.77:06
Richard Brittain takes a shot.75:49
Corner taken right-footed by Paul Lawson from the left by-line, save by Radoslaw Cierzniak.75:49 Substitution
Substitution Steven Ross on for Rocco Quinn.73:40
Free kick awarded for a foul by Paul Lawson on Gary Mackay-Steven. Willo Flood takes the free kick.72:10
Direct free kick taken by Brian McLean.72:10 Substitution
Substitution Luke Johnston on for John Rankin.
Foul by Rocco Quinn on Willo Flood, free kick awarded.70:10
Shot by Iain Vigurs from deep inside the penalty area misses to the left of the goal.68:41
Radoslaw Cierzniak takes the free kick.68:41 Booking
Booking The referee shows Iain Vigurs a yellow card.68:16
Richard Brittain restarts play with the free kick. The referee blows for offside.68:16 Booking
Booking Jon Daly shown a yellow card.68:05
Evangelos Ikonomou fouled by Jon Daly, the ref awards a free kick.67:06 Substitution
Substitution Rory Boulding replaces Ryan Gauld.66:55
Shot by Paul Lawson from a long way out goes over the crossbar.66:08
Rocco Quinn has an effort at goal from outside the penalty box which goes wide left of the goal.64:01
Richard Brittain restarts play with the free kick.64:01 Dismissal
Dismissal Red card for Barry Douglas.63:44
Barry Douglas gives away a free kick for an unfair challenge on Ivan Sproule.59:08
The assistant referee signals for offside against Jon Daly. Free kick taken by Michael Fraser.56:44
Rocco Quinn gives away a free kick for an unfair challenge on Stuart Armstrong. Shot comes in from John Rankin from the free kick.55:13
Free kick awarded for an unfair challenge on Jon Daly by Andre Hainault. Direct free kick taken by Barry Douglas.54:19
Richard Brittain fouled by John Rankin, the ref awards a free kick. Andre Hainault takes the free kick.53:17
Assist on the goal came from Iain Vigurs.53:17 Goal scored
Goal! - Ivan Sproule - Ross Co 1 - 0 Dundee U Ivan Sproule grabs a headed goal from close in. Ross County 1-0 Dundee Utd.52:02
Free kick awarded for a foul by Rocco Quinn on Gary Mackay-Steven. Strike comes in from Barry Douglas from the free kick, save made by Michael Fraser.51:08
Effort from just outside the area by Richard Brittain goes over the target.49:49
Corner taken left-footed by Barry Douglas, Evangelos Ikonomou makes a clearance.45:14
Iain Vigurs gives away a free kick for an unfair challenge on Willo Flood. Direct free kick taken by Willo Flood.45:01
The second half has started.45:00 +0:03 Half time
Half Time The ref blows to end the first period.43:10
Richard Brittain takes a shot. Blocked by Brian McLean.39:07
Mihael Kovacevic challenges Gary Mackay-Steven unfairly and gives away a free kick. Barry Douglas takes the direct free kick.37:48
Foul by Ryan Gauld on Iain Vigurs, free kick awarded. Free kick taken by Iain Vigurs.34:52
Corner from the right by-line taken by Iain Vigurs, John Souttar manages to make a clearance.33:51
Mihael Kovacevic produces a right-footed shot from outside the penalty area and misses left.32:02
Free kick awarded for a foul by Richard Brittain on Gary Mackay-Steven. Barry Douglas restarts play with the free kick.30:05
Corner taken by Barry Douglas played to the near post, clearance by Evangelos Ikonomou.28:55
Evangelos Ikonomou challenges Gary Mackay-Steven unfairly and gives away a free kick. Free kick taken by Barry Douglas, Jon Daly takes a shot. Save made by Michael Fraser.27:53
Gary Mackay-Steven concedes a free kick for a foul on Evangelos Ikonomou. Free kick taken by Richard Brittain.27:10
Paul Lawson takes a shot. John Souttar gets a block in.23:04
Free kick awarded for a foul by Gary Mackay-Steven on Steffen Wohlfarth. Michael Fraser restarts play with the free kick.18:36
Richard Brittain takes the free kick.18:36 Booking
Booking Booking for John Souttar for unsporting behaviour.18:26
John Souttar is penalised for a handball.17:20
Unfair challenge on Ivan Sproule by Barry Douglas results in a free kick. Richard Brittain takes the direct free kick.16:38
Shot by Evangelos Ikonomou from just outside the area goes over the net.16:19
Steffen Wohlfarth takes a shot. Brian McLean gets a block in.14:28
Inswinging corner taken by Barry Douglas from the right by-line played to the near post, Header from close range by Jon Daly misses to the right of the goal.13:16
Free kick awarded for a foul by Richard Brittain on Barry Douglas. Barry Douglas takes the free kick.8:20
Shot by Steffen Wohlfarth from a long way out goes over the target.4:28
Iain Vigurs has an effort from just inside the box that misses to the left of the goal.3:35
Stuart Armstrong is penalised for a handball. Shot on goal comes in from Richard Brittain from the free kick.2:49
Iain Vigurs takes a shot. Save made by Radoslaw Cierzniak.1:09
The assistant referee flags for offside against Ivan Sproule. Direct free kick taken by Barry Douglas.0:51
Gary Mackay-Steven is adjudged to have handled the ball. Grant Munro restarts play with the free kick.0:00
The referee gets the game underway.
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