Carlisle United 0, Oxford United 2 (Maguire pen 4, Sercombe 73)

An incredible 2,283 away fans made the 550-mile round trip to cheer Michael Appleton’s side one step closer to Sky Bet League One.

And they made an ideal start, with Maguire converting from the penalty spot in the fourth minute after he was fouled in the box.

United squandered several good chances before having to weather a nervy spell after the break.

With their promotion rivals winning, only a 14th victory on the road would have kept Appleton’s side in the top three.

But just as the pressure was building, Sercombe hammered home a low shot to double the lead.

It ensured a trouble-free end to the game for United, who now know a win against Wycombe Wanderers at the Kassam Stadium next Saturday will secure promotion.

The teamsheet showed one change from the side which started the 2-0 win at home to Hartlepool United a week earlier.

Top scorer Kemar Roofe failed a fitness test so dropped out, promoting Callum O’Dowda.

Roared on by a fantastic turnout from the travelling fans, United made the dream start.

A quick break in the third minute saw Danny Hylton beat his man out wide and slide a pass into O’Dowda, who found Maguire.

The Scot was felled in the box by Luke Joyce and coolly went on to despatch the penalty, sending goalkeeper Mark Gillespie the wrong way.

Carlisle were wobbling and if Hylton had got hold of his shot a minute later Gillespie would have been struggling.

United sensed blood and before the game was 11 minutes old Hylton had headed wide and O’Dowda rolled a shot just the wrong side of the post.

The one-sided start quickly agitated the home fans, but their side was able to steady the ship.

While Carlisle’s play-off hopes had ended a week earlier, this was not a team with their minds on the beach.

Joyce fired a low shot just wide from range, while Jake Wright was twice well placed to make important blocks, the latter to keep out a well-struck shot from Jason Kennedy.

United were no longer dominating the ball, but they looked a real threat on the break against a Carlisle side which had switched to a back three.

Midway through the half O’Dowda rolled his man and drove forward, before finding a sprinting Alex MacDonald.

The winger was in a good position, but instead of shooting from the edge of the box he attempted a tricky return pass which evaded O’Dowda.

The Ireland Under 21 international had another chance just after the half-hour mark. This time he beat Danny Grainger on the edge of the box but fired inches wide.

United held their lead at the break, but knew a second goal was vital.

It almost arrived via a terrible error from Gillespie seven minutes after the restart, when Maguire intercepted his pass. Fortunately for the goalkeeper he gathered again just before the ball crossed the line.

Carlisle had made a double change at the break and went on to have their best spell of the game.

Both substitutes came close – Jack Stacey fizzing a shot just wide from 20 yards, while Alex Gilliead was denied by an excellent block from Benji Buchel.

United claimed a penalty on 67 minutes when Hylton was brought down by Tom Miller, but the referee awarded a free-kick half a yard outside the box, which Maguire fired over.

But back came Carlisle and they had a strong shout for a penalty when Jonjoe Kenny blocked a cross with his arm.

The referee gave a corner, from which United wobbled but Hylton somehow hacked a shot off the line and over the crossbar.

Nerves were jangling, so there was a huge sense of relief when Sercombe came up trumps 17 minutes from time.

Another break fell to O’Dowda, who this time found the midfielder to hammer a low shot under Gillespie from 12 yards.

• Liam Sercombe is congratulated after doubling the lead

It sparked an incredible reaction from the United fans behind the goal, many of whom had set off for the game on Friday.

With Carlisle chasing the game, chances started to come quickly for the visitors.

Substitute Jordan Bowery’s fierce shot was pushed on to the post by Gillespie, who then denied Sercombe.

The fight finally went out of Carlisle in the closing stages, as United ran down the clock to secure a precious three points.

Carlisle Utd: Gillespie, Ellis, Miller, Grainger, McQueen, Joyce, Comley (Stacey HT), Kennedy, Brough (Gilliead HT), Wyke (Asamoah 83), Ibehre.

Unused subs: Hanford, Atkinson, Smith, Sweeney.

Oxford Utd: Buchel, Kenny, Dunkley, Wright, Skarz (Lundstram HT), MacDonald (Bowery 72), Sercombe, Ruffels, Maguire, O’Dowda, Hylton (Waring 84).

Unused subs: Slocombe, Long, Roberts.

Referee: Phil Gibbs (West Midlands).

Attendance: 6,948 (2,283 visitors).