Oxford United suffered a late FA Cup heartbreak at the Pirelli Stadium yesterday as they fell to a winner five minutes from the end of their first-round tie.

Burton substitute Aaron Webster, normally a defender but who had just been pushed up front by his manager, powered home a far-post header from Scott Malone’s hanging cross.

Until then, it looked as though a much-changed United team had done enough to earn a replay, and gain their first clean sheet since Hereford on September 11.

It was a cruel blow for Chris Wilder’s team, who were put under constant pressure in the first half, but weathered it, and then started to create opportunities with much more of the play in the second.

Oxford were without skipper James Constable, who had been taken ill, and with Jack Midson having gone out on loan to Southend until December 29, that meant a change to two up front and a 4-4-2 formation for the first time this season.

Manager Chris Wilder dropped Simon Heslop and Asa Hall to the bench as Steve Kinniburgh and Simon Clist came in for their first starts (excluding the Johnstone’s Paint Trophy).

Clist joined Josh Payne in central midfield, with Damian Batt and Anthony Tonkin operating as the wide midfielders in front of fullbacks Ben Purkiss and Kinniburgh.

Albion were without their giant centre back Darren Moore, who was suspended for picking up five bookings, and he had a hamstring injury as well.

United would have gained some confidence from the fact that they had never lost at Burton, and also because Burton manager Paul Peschisolido did not have a good record in cup competitions.

In his second season at the Pirelli Stadium, he had managed only one win in six cup ties, and that was against Oxford City in the FA Cup last season, when they needed a very late winner.

It was all Burton in the opening stages as they took the game to the U’s straight from the off.

Kinniburgh cleared a James Collins shot off the line at a corner in the third minute, and Russell Penn drove an angled shot across the face of the goal soon after.

And the former Rangers defender was quick to whip the ball away from Collins’ foot when Collins broke clear on the right.

Adam Bolder ran through and around Ryan Clarke, but Tonkin got back to whisk the ball away for a corner.

Oxford’s back line was under constant pressure as they were not able to retain possession further up the field, and when a Bolder shot deflected up into the air, Clarke did just enough to put Collins off his shot.

One very brief respite from the one-way traffic came when Tom Craddock met Damian Batt’s right-wing cross but couldn’t get over the header and it flew well over.

Alfie Potter replaced Kinniburgh on 25 minutes to give the visitors a bit more going forward, though it seemed hard on the Scot, who had done well.

Purkiss gave the ball away cheaply and almost paid the price as Burton broke quickly for John McGrath to finish with a shot that Clarke saved well.

Both centre halves, Mark Creighton and stand-in skipper Harry Worley, were having to work overtime and both were defending well.

When Creighton did make a mistake, he responded with a great recovery tackle, and in an instant Clist chipped the ball over the top for Potter, whose run and cross might easily have been turned in.

Having been under pressure for so long, the U’s almost snatched a goal right on half-time as Payne set Craddock free on the left of the box. With Green waiting in the middle, Craddock tried his luck with an angled shot that keeper Adam Legzdins couldn’t hold, and it rebounded off Green but away from the goal.

For the second half, United brought on Hall for Purkiss, reverted to 4-3-3 and they showed much more attacking intent.

Green was yellow-carded for leaving his foot in on the keeper, though it seemed more accidental than anything.

Midway through the half, Payne’s superb first-time ball released Craddock, who made a bit of a mess of it, seemingly caught in two minds between a shot and a cross.

But there seemed more purpose and self-belief about United and they began to break forward with ever-increasing menace.

If anything, Burton’s goal came against the run of play.

Soon after it, Craddock had a chance to level when the ball dropped loose in a crowded box, but his shot deflected wide.

Burton are at home to Chesterfield in the second round.

For Oxford United, it has been a week to forget.