SAM Slocombe made two costly errors as Oxford United were denied victory by a last-minute Mansfield Town goal at the Kassam Stadium tonight.

The hosts thought they had done enough after Danny Hylton’s double, but Jack Thomas nodded in a dramatic 89th-minute equaliser when Slocombe fumbled after Ryan Tafazolli's header came back off the bar.

Victory would have seen Michael Appleton’s side open up a seven-point gap over fourth-placed Bristol Rovers in Sky Bet League Two, but instead their advantage remains at four points, with the draw seeing Mansfield climb into fourth place.

It did not go to plan early on for the hosts when Matt Green headed the Stags into the lead after Slocombe did not get a good connection on an attempted punch, allowing the former Oxford striker to head home from close range.

However, Hylton’s brace either side of half-time put United ahead and seemingly on course for an important three points.

But Thomas took full advantage of Slocombe's error to leave the hosts frustrated.

United made two changes from the Johnstone's Paint Trophy area final second leg against Millwall last week.

Chris Maguire started his first game since returning to the club, while goalkeeper Sam Slocombe came in for Benji Buchel.

After an uneventful opening ten minutes, it was the Stags who created the first meaningful effort, with Jake Wright forced to head away a goal-bound effort from Matt Blair.

Mansfield shaded the opening quarter of the game, while United looked like a side that had not played for seven days after Saturday's postponement at Exeter.

And the visitors took the lead on 23 minutes when Slocombe spilled a Benning cross under pressure from Ryan Tafazolli and Green headed home.

It was perhaps the wake-up call United needed and just a minute later Hylton's looping header landed on the roof of Scott Shearer's net.

But the Stags continued to have the upper hand and Green was denied a second when Jonjoe Kenny cleared off the line.

However, the host's best flurry forward moments later brought the equaliser.

Liam Sercombe spotted Kenny's run and the full back dug out a cross from the dead ball line for Hylton to head home on 31 minutes.

Suddenly United were alive and dominating possession, while Alex MacDonald and Kenny were causing Mansfield problems down the right.

But the Stags were still a threat with the pace and strength of Green, while Slocombe pulled off a fine one-handed save to claw a James Baxendale volley out of the top corner on 41 minutes.

United started the second half positively, with Kemar Roofe heading wide, before Sercombe drilled a shot straight at Shearer and Maguire tried his luck from 25 yards.

But the pace of Green and Reggie Lambe still caused the hosts problems and the former kept Slocombe on his toes with a rasping drive on 52 minutes.

Mansfield, though, we're happy to waste time when possible, and it was United building the pressure.

Roofe saw a shot deflect over after good work from Kenny, but on 69 minutes their good work paid off.

Substitute Zeli Ismail found space on the right and his cross was flicked on by Roofe for Hylton to hammer into the top corner.

The U's had their tales up and Maguire went close to making it 3-1 when his free-kick hit a post on 75 minutes.

United looked comfortable, but they were hit with a hammer blow.

Mansfield hit a long ball into the box and after Tafazolli's header hit the bar, Slocombe could not hold onto the ball and substitute Jack Thomes nodded into the net.

There was still a chance to win it, but Hylton fired wide from inside the six-yard box.

Oxford United (4-4-2): Slocombe, Kenny, Mullins, Wright, Skarz, MacDonald (Ismail 64), Lundstram, Sercombe, Maguire (O'Dowda 78), Roofe (Bowery 86), Hylton.

Unused subs: Buchel, Ruffels, Dunkley, Evans.

Mansfield Town (4-3-3): Shearer, Collins, Pearce, Tafazolli, Benning, McGuire, Lambe (Thomas 71), Clements, Baxendale (Beardsley 62), Blair (Alfei 67), Green.

Unused subs: Jensen, Chapman, Yussuf, Kavanagh.

Referee: Michael Bull (Essex).

Attendance: 5,346.