Andy Dorman came back to haunt Dundee United with an equaliser at the end of a second half that the home side had totally dominated at Tannadice.

Sean Dillon volleyed home in the 69th minute following some intense United pressure and Noel Hunt later had a goal disallowed.

But Dorman, whose goal knocked United out of the Scottish Cup two weeks ago, smashed home a leveller two minutes from time to dent United's UEFA Cup hopes.

Days after they had dominated a goalless draw with Falkirk, United's profligacy again undermined their bid for third place in the Clydesdale Bank Premier League.

Despite missing a series of chances, they looked like overhauling Motherwell, but a late equaliser for the Steelmen at Aberdeen and Dorman's sucker-punch leaves them three points adrift.

United boss Craig Levein rested Christian Kalvenes and Prince Buaben, who was struggling with a hamstring strain, with Willo Flood and Danny Grainger coming in.

St Mirren winger Mark Corcoran replaced Hugh Murray following the late defeat by Celtic and Mark Howard continued in goal, while Chris Smith made the bench following illness.

United keeper Lukasz Zaluska had to back-track to catch Ian Maxwell's overhit cross in the first minute but both sides cancelled each other out in the opening stages.

Will Haining atoned for an error to block Hunt's shot before a Darren Dods mistake at the other end handed Saints a chance.

Corcoran intercepted the defender's sloppy pass but Zaluska was well-placed to save Craig Dargo's 20-yard volley.

Howard soon blocked a close-range volley from Mark de Vries after Dods had headed on a Danny Swanson corner.

St Mirren survived a penalty claim when Hunt fell over Dorman's outstretched foot while Grainger's tackle prevented Corcoran bursting through on goal.

United came closest to breaking the first-half deadlock in the 21st minute when Flood's powerful 25-yard strike hit the crossbar and bounced onto the roof of the net as De Vries and Howard scrambled for the rebound.

St Mirren missed their best chance of the half four minutes later when Corcoran shot over from 15 yards following Dargo's pull-back.

United could not make them pay though as De Vries headed well off target when Grainger found him unmarked 10 yards out.

Howard then got down well to save a low 20-yard shot from Morgaro Gomis before Lee Wilkie was booked before the break for bringing down Dorman as the visitors broke.

The Saints keeper almost gifted United the lead when he dithered on a kick-out which Noel Hunt charged down, but the ball bounced off the Irishman's knee and over the bar.

A short backpass from Wilkie almost let Billy Mehmet in at the other end, with the defender grateful to Zaluska for winning the 50-50, but United were stepping up the pressure.

Hunt met Flood's dangerous cross but Howard brilliantly clawed the ball after the forward's header had deflected off Haining.

Jim O'Brien replaced Swanson as United looked for the cutting edge to complement their increasing dominance, but Zaluska again came to their rescue when he dived to save after Dorman's cross had hit off Dargo's thigh.

Hunt headed over from Flood's cross and O'Brien's powerful effort bounced off Maxwell's back and wide for a corner.

However, pressure told when Grainger's deep cross found his fellow full-back Dillon unmarked, and the Irishman cushioned a volley into the bottom corner.

Dargo was booked for fouling O'Brien before being replaced by Jim Hamilton as Saints struggled to get out their own half.

United seemed to have clinched in the 84th minute when Hunt back-headed Flood's cross into the far corner but the linesman's flag was raised.

Saints did not look like levelling until the 88th minute when Dorman lashed home from 12 yards after Mehmet had won a Maxwell free-kick into the box.

Teams

Dundee Utd Zaluska, Dillon, Wilkie, Dods, Grainger, Flood,Kerr, Gomis, Swanson (O'Brien 60), Hunt, De Vries.

Subs Not Used: McLean, Robertson, Conway, Kenneth, Buaben,

Odhiambo.

Booked: Wilkie.

Goals: Dillon 69.

St Mirren Howard, van Zanten, Haining, Potter, Maxwell,Corcoran, Mason (Kean 88), Dorman, Barron, Mehmet,Dargo (Hamilton 78).

Subs Not Used: Smith, Murray, Miranda, McCay, McGinn.

Booked: Dargo, Corcoran.

Goals: Dorman 88.

Att: 6,037

Ref: I Brines (Scotland).