James Constable marked his signing of a new three-year contract with two second-half goals at the Kassam Stadium as Oxford United again showed their magnificent spirit by coming from behind to maintain their play-off hopes.

The U's were stunned when Histon took a shock lead on 17 minutes.

And although the visitors were reduced to ten men in the first half when strker Danny Wright was sent off, the Cambridgeshire outfit defended well under strong pressure to hold out until midway through the second half.

But then Constable came into his own, showing what a fantastic finisher he is.

He levelled on 66 minutes, and fired in the winner with just six minutes to go, tally to take his tally for the season to a remarkable 24 goals.

Third-placed Histon stunned the big crowd by taking the lead and it came when Luke Foster was off the pitch, receiving treatment.

Jack Midson found himself in space on the left 25 yards out and with the home defence stretched, he cleverly chipped over Billy Turley from 25 yards out for a fine finish.

But ten minutes later the Stutes found themselves down to ten men. Wright collided with Turley, who lay prone on the ground, and referee Simon Beck produced the red card, presumably having seen an elbow.

United tried to move the ball around and use the full width of the pitch after that, and chances came.

Adam Murray's deft pass in to Craig Farrell almost got the striker free, only good defending by Matthew Langston saving the visitors, and moments later a superb crossfield run and cross by Lewis Haldane was nearly turned in by James Constable.

Haldane had been Oxford's best player in the first half, constantly putting his head down and running hard, to turn defensive situations into attacking ones.

Kevin Sandwith also produced some quality crosses from the left, Farrell meeting one with a glancing header wide.

Just before the break, Constable fired in an angled drive which beat goalkeeper Danny Naisbitt, and he was very unfortunate to see the ball hit the far post and come back out. Craig Nelthorpe, following up, tried his luck from a very tight angle, and Naisbitt blocked.

Oxford piled on the pressure in the second half, with Murray spreading play beautifully at times, but they just couldn't find a way through.

Sandwith sent a left-foot volley arrowing just past the post, and Adam Chapman hit a rasping 25-yard shot against the foot of Naisbitt's right upright, with Farrell unable to connect properly with the rebound.

The home side had a scare when Turley fumbled Matthew Langston's header by his left post, and another when Nat Mitchel-King planted a header from Gareth Gwillim's free-kick narrowly wide.

But on 66 minutes Constable fired home the equaliser with a left-foot shot on the turn after Craig Nelthorpe had seen his shot blocked.

Chris Wilder's team kept pressing, and thought they had a penalty when Haldane cut into the box after a brilliant 50-yard sprint, and was brought down by Lanre Oyebanjo. But the ref deemed the foul just inches outside the area, and the free-kickcame to nothing.

Wilder sent on Yemi Odubade for the last 16 minutes to operate with wingers on both flanks.

And on 84 minutes, the U's got the goal they deserved. Chapman and Farrell both had shots blocked, and when the ball ran free to Constable, he smashed it into the goal - to the delirium of the fans.

Oxford Utd: Turley, Chapman, Willmott, Foster, Sandwith; Haldane, Murray, Clist, Nelthorpe (Odubade 74), Farrell, Constable. Subs not used: Hinchliffe, Day, Carruthers, Hutchinson.

Att: 6,231