Carlisle left it late to claim all three points on a dramatic afternoon at Brunton Park as they came from behind, to the delight of the home crowd, courtesy of second half goals from Mark Beck and Brad Potts.
United had slightly the better of a tight start as White and Potts combined on the right flank. The first real opening of the day came when Elliott and Dempsey exchanged passes to edge their way towards the box. Iliev pulled clear and his first touch made space for a toe poke which Clarke was able to gather.
Carlisle had a strong wind in their favour and Dempsey utilised it to good effect when he swung a deep free kick into the box. Beck won the header and Iliev was disappointed to see his 19-yard volley fly just over the target.
The Cumbrians had to defend moments later when Barnett drilled a shot into the Warwick and Riley did well to get to the byline as the yellow shirts stayed forward. Grainger did well to recover and clear the danger before Hylton could make a mark.
The hosts continued to look the more likely and a half clearance from a Dempsey corner sat invitingly for Marrow. He struck it well but a block sent it behind despite the good connection. A flap from Clarke from the resulting set piece gave Grainger a chance to pick out Beck and the big striker was within an inch of opening the scoring with a glancing header which flew just past the post.
It had been almost total domiantion for the Blues but Rose and Hylton moved intelligently to carve a way through. Grainger held his position, and Meppen-Walter completed a vital block, and the pair were able to close the door and hook the ball away.
A slip on the half way line allowed Riley to burst through in what was a good spell but he had a rush of blood to the head as he bore down on goal. An unfortunate touch from his left boot resulted in an embarrassing shot with his right as the moment fizzled away.
The right wing remained a good route of attack for Carlisle and Marrow called for it from Dempsey has he pulled off his man. Another nod down from Beck brought another link up with strike partner Georg Iliev but he needed a touch and two defenders stepped in to rob him of his glory.
Having controlled long periods of the first half the Cumbrians were undone on the stroke of half time when Rose dinked a lovely ball over the top. Hylton used pace and power to carry it forward and he made no mistake with a crunching finish into the bottom corner.
Mark Beck raised home spirits at the start of the second period when he spun on a pass from Potts. He hit it early from distance and Clarke had to dive as it raced past his upright. United went close again when a lovely touch from Dempsey set Elliott on the attack. He dropped a shoulder and Clarke was relieved to see a deflected shot bobble just past the post.
Stephen Elliott had to leave the field of play when he received a long period of treatment but Carlisle kept finding the good positions with Potts and Amoo crossing at every opportunity.
Carlisle reshaped and regrouped and they levelled the scores when Potts pulled away from his man into acres of space. He had time to pick his pass and Mark Beck did the rest with an unstoppable header from close range.
Barnett sent one wide from a tight angle as Oxford remained a threat and Roberts had to be watched by Meppen-Walter when he lurked with purpose.
But it was Carlisle who asked the questions and Dempsey rattled a stinging shot into the stands when he was picked out by Marrow. Asamoah was disappointed in the next attack when his volley followed the same route as it spun up off his boot.
And they got their just rewards on 90 minutes when Derek Asamoah arrived late to finish off a low delivery from a Dempsey set piece at the front stick. Oxford threw men forward in time added on and Barnett and Holmes-Dennis went close, but the Cumbrians did enough to see it through to a very well earned victory.
United - Beck (73), Asamoah (90)
Oxford - Hylton (45)
United - Marrow (49)
Carlisle United - Hanford, White, Grainger, Meppen-Walter, Brough, Potts, Marrow, Dempsey, Elliott (Amoo 59), Beck, Iliev (Asamoah 59). Subs - Eccles, Robson, Sweeney, Dicker, Gillies.
Oxford United - Clarke, Mullins, Wright, Rose (Roberts 78), Hylton, Potter (O'Dowda 61), Whing, Cullins, Riley, Barnett, Holmes-Dennis. Subs - Meads, Raynes, Ruffels, Long, Jakubiak.
Referee - Mr Mick Russell
Attendance - 4,392 (362 away fans)