Oxford United’s play-off hopes took a further dent tonight when they fell to a second successive defeat.

Two own goals in a horrific four-minute spell midway through the second half did the damage for Chris Wilder’s team.

The decisive third Lincoln goal was an awful moment for left back Anthony Tonkin, who sliced Mustapha Carayol’s low cross into his net for an embarrassing own goal.

After their home defeat by Hereford last Saturday, this was a severe blow for the U’s, who had a bad time at the back on a cold night at Sincil Bank.

Before that, they were reflecting on the benefit of shooting when they get the chance as they came from behind to equalise before the break.

After falling behind in the fifth minute, United got back on level terms when Tom Craddock tried his luck with a low shot from the edge of the penalty area five minutes before half-time.

It should have been a comfortable save for Imps goalkeeper Trevor Carson, but he spilled it, and Steve MacLean pounced to lash it into the roof of the net from six yards.

Unchanged for the second match running, Oxford made a bright opening and MacLean twice found space down the right as they attacked from the off.

It seemed as though they were intent on getting shots in earlier than they had against Hereford when Simon Heslop beat his man and then fired in an angled right-footed drive that flashed wide.

But in the fifth minute it became a disastrous start as they were caught asleep at the back.

No-one picked up Josh O’Keefe, who met Gavin McCallum’s cross from the left with hardly the best of shots with the outside of his right foot.

But Ryan Clarke was wrong-footed by it, and when the ball then hit his right post and bounced back into play, he was helpless as O’Keefe knocked it into an empty net.

The U’s soon got back into it, although the understanding was not always there. On one break through the middle, James Constable played a pass for Tom Craddock to run onto, but he had already stopped in his tracks.

And when Heslop tried to play a ball to MacLean on the edge of the area, ity was horribly overhit.

On a couple of occasions, Constable took it upon himself to dart out right, and then delivered good crosses towards MacLean, who had filled the space in the middle.

They worked the ball smartly, on a five-man move, to Tonkin, overlapping on the left, but his cross was too deep for the strikers.

Lincoln almost made it 2-0 on 33 minutes when Ashley Grimes met a low left-wing cross first-time, and very sweetly. Clarke would not have stood a chance had it been on target, but it arrowed a yard wide.

The visitors seemed to drive forward more as the half wore on, with Constable working tirelessly, and five minutes before the break, they levelled.

After good work by Tonkin on the left, Craddock tried a shot from the edge of the box, which Carson spilled, and MacLean pounced.

Their confidence lifted, Constable attempted an 18-yard drive which had plenty of power, but kept rising as it flew over the bar.

Early in the second half, after a break initiated by Tonkin, MacLean and Craddock combined well, and Craddock finished with a fierce left-footed drive on the turn that was not far over.

However, the home side then got on top.

Jake Wright showed his fierce determination with a terrific block on Delroy Facey.

But 18 minutes into the second half, Facey was free to hook in a shot on the turn from 14 yards, from Mustapha Carayol’s right-wing cross, and Harry Worley could only help it into the goal.

And four minutes later, it went from bad to worse for United.

This time Carayol crossed low from the left, and Tonkin, facing his own goal sliced his clearance horribly into the net from eight yards to make it 3-1.

Simon Hackney, Alfie Potter and Jack Midson all came on to try to help United get into the contest again, but there was no way back after that nightmare four minutes.