DUNDEE secured a first derby victory over rivals United since November 2004 to move into the top six of the Scottish Premiership.
The Dark Blues’ top scorer Greg Stewart opened the scoring on 13 minutes when his 20-yard shot slipped through the grasp of United goalkeeper Radoslaw Cierzniak.
But the visitors levelled instantly as Nadir Ciftci netted from the penalty spot after Chris Erskine’s effort was blocked by the hand of Dundee captain Kevin Thomson.
In an enthralling encounter at Dens Park, Dundee regained their lead midway through the first half when James McPake powered Stewart’s corner past Cierzniak from close range with a bullet header.
The second half brought less excitement with United on top for large periods but Paul Heffernan tapped home another delightful Stewart cross for his first Dundee goal to settle the issue.
It ensured Jackie McNamara’s men could not prevent a fifth successive defeat, the Tangerines’ worst run of form since 2006, while their winless run extended to 10 games.
In contrast, Dundee have lost just one of their last 12 games and are yet to taste defeat at home in the league in 2015 as Paul Hartley’s side seek to consolidate a top-half finish prior to the split.
United had won the previous three meetings this season between the two city rivals, who are a mere 30 yards apart on Tannadice Street in the City of Discovery.
And Dundee made their intentions clear early on with Jim McAlister testing Cierzniak before the Polish custodian dropped a clanger to let Stewart fire his 15th goal of the campaign.
The response was immediate as United restored parity after referee John Beaton adjudged that Thomson had handled in the box with top-scorer Ciftci sending Scott Bain the wrong way for his 14th of the campaign before being booked for blowing kisses towards the Dundee stopper.
Dundee, though, re-established their advantage minutes later when McPake, a doubt before the game with a knee complaint, got infront of Jaroslav Fojut to notch his first goal since August.
United almost snatched an equaliser when Calum Butcher’s header was cleared off the line by Thomson before Paul McGowan was denied by a flying stop from Cierzniak in an end-to-end contest.
The Terrors wrestled some of the initiative back after the interval but rarely threatened and the hosts gained an unassailable lead when Stewart’s low cross was tapped home at the back post by on-loan Hibernian striker Heffernan.
The margins could have been greater in Dundee’s favour with Cierzniak pulling off a fine one-handed save to deny Stephen McGinn’s header from a Heffernan delivery.
Ecstatic Dundee supporters aimed tongue-in-cheek chants of ‘You’re getting sacked in the morning” towards a beleaguered McNamara as they recorded a famous first derby win in 11 years which leaves them just two points behind their neighbours.
United, meanwhile, remain fourth in the table as their confidence crisis shows no signs of abating and a failure to stop the rot sooner rather than later may have damaging consequences in the concluding weeks of a season which promised much for so long.
Substitutes: Davidson (on for McAlister 74′), Harris (on for Stewart 84′), Heffernan (on for Clarkson 86′).
Not used: Letheren (GK), Ferry, Gadzhalov, Wighton.
Booked: McGinn (8′), Thomson (15′), Dyer (37′)
Goals: Stewart (14′), McPake (23′), Heffernan (68′)
Substitutes: Spittal (on for Anier 45′), Bilate (on for Connolly 67′), Muirhead (on for Butcher 75′).
Not used: Szromnik (GK), Souttar, Paton, Telfer.
Booked: McGowan (16′), Butcher (64′), Bilate (72′), Rankin (85′)
Goals: Ciftci (16′ pen)
Referee: John Beaton (Scotland) – 7/10