CONOR McAleny bagged his first career hat-trick as Oxford United strengthened their Sky Bet League One play-off push by tearing struggling Chesterfield to pieces.

After Rob Hall opened the scoring with a tap-in, the Everton loanee took centre stage.

A sumptuous volley made it 2-0 before half-time and he followed it with a carbon copy of his midweek winner at Charlton Athletic to make the game safe.

There were still 20 minutes remaining when he completed his hat-trick, during which United had ample chance to run up a cricket score.

One more unanswered goal would have set a new club record for the biggest away win in the Football League, but it took none of the gloss off a terrific result.

It took Michael Appleton’s side up to ninth place in Sky Bet League One, their highest position of the season and narrowed the gap to the play-offs to four points with games in hand.

There were eyebrows raised when the teamsheet was published and had John Lundstram, Ryan Ledson and Marvin Johnson named among the substitutes.

Hall and Chris Maguire, rested for the midweek win at Charlton Athletic, returned to the side, while Josh Ruffels made his first league start since October.

Chesterfield came into the game six points from safety at the wrong end of the table.

In blustery conditions and driving rain they made the better start, with Reece Mitchell on the left flank providing their main threat.

But United steadily found their feet, though and McAleny had a couple of early sights of goal.

He saw a first-time effort from Hall’s pass saved by goalkeeper Thorsten Stuckmann, before a minute later a better opportunity went begging with a scuffed connection after Ruffels’s cutback.

The conditions made life difficult for defenders on both sides and it played a role in the opening goal, on 17 minutes.

Joe Skarz’s ball forward skidded on the wet turf and was misjudged by Sam Hird, allowing Toni Martinez to ease the defender off the ball.

The West Ham loanee drove into the box, where he unselfishly squared for Hall, who cheekily dummied to shoot and after Stuckmann was floored, the U’s winger tapped in.

Herald Series:

  • Rob Hall opens the scoring in the 17th minute

Chesterfield pushed in search of a quick response.

They almost got it when Phil Edwards’s slide tackle on David Faupala ricocheted to send Kristian Dennis through on goal, but Simon Eastwood parried his powerful 20-yard shot.

The Spireites played an ambitious 3-4-3 system, with the experienced Sylvan Ebanks-Blake leading the line.

The former Wolverhampton Wanderers hitman showed a flash of his quality just after the half-hour mark with a snap-shot from 30 yards which flew just over Eastwood’s crossbar.

United had barely threatened since the goal, but ten minutes before the break their lead was doubled in fine style.

A loose clearance from Stuckmann was intercepted by Edwards and the ball was crisply moved on through Hall and Sercombe, before the ball looped up to McAleny.

The forward on loan from Everton did not hesitate, smashing a volley from 25 yards which left Stuckmann grasping at thin air.

Herald Series:

  • Conor McAleny doubles Oxford United's lead with a high-quality volley

It was a sensational strike and United’s threat prompted Spireites boss Gary Caldwell to make a substitution before the break.

The visitors started the second half in a hurry.

Stuckmann turned a low Hall shot round the post and from the resulting corner the goalkeeper made a superb one-handed stop to claw out Edwards’s downward header.

Martinez then sent McAleny through with a clever pass, but his shot was blocked by Ian Evatt.

United’s progress was briefly slowed by the sorry sight of Hall limping off with a hamstring problem, replaced by Joe Rothwell.

The visitors had lost their searing pace, but carried on regardless.

McAleny made it 3-0 on the hour with a goal uncannily similar to his 25-yard effort which won Tuesday’s game at the Valley.

It got even better for him nine minutes later.

Stuckmann was again caught over-playing around his penalty area and Sercombe intercepted an ill-advised pass.

He squared for McAleny, who steadied himself before beating the exposed goalkeeper.

Herald Series:

  • Conor McAleny adds his third goal of the afternoon

It snuffed out any lingering hopes for the hosts, who had just had a goal by substitute Ched Evans ruled out for offside.

United were hungry for more and should have quickly added to their tally.

McAleny shot wide from a Rothwell cross, before Stuckmann smothered Maguire as he attempted to round the goalkeeper.

Even when Chesterfield got forward, they ended up coming under attack.

When one corner was cleared, McAleny got the better of Hird and United charged forward, with Martinez seeing his shot well saved.

“We want five” chanted the away end as Sercombe came closest to netting late on, volleying one effort wide and testing Stuckmann with another.

It was not to be, but United had long since made the game safe.

Chesterfield (3-4-3): Stuckmann, Hird, Evatt, Jones (Kakay 43), Grimshaw, Gardner (Evans 65), Martinez, Mitchell, Faupala (Simons 81), Ebanks-Blake, Dennis.

Unused subs: Allinson, Brown, Anderson, Humphreys.

Oxford Utd (4-4-2): Eastwood, Edwards, Dunkley, Nelson, Skarz, Maguire, Sercombe, Ruffels, Hall, McAleny, Martinez.

Subs used: Rothwell (Hall 54).

Unused subs: Stevens, Ribeiro, Lundstram, Ledson, Johnson, Hemmings.

Referee: David Webb (County Durham).

Attendance: 5,901 (960 visitors).