Queens Park Rangers 0-2 Manchester United

Marouane Fellaini was introduced as a half-time sub for Juan Mata

• Half-time sub Marouane Fellaini gives United the lead

• Falcao fails to score after being recalled to starting XI

• QPR boss Harry Redknapp denies his job is under threat

• Defeat leaves Rangers one point from safety

Manchester United bounced back from the home defeat by Southampton to maintain their pursuit of a top four place and increase pressure on Queens Park Rangers manager Harry Redknapp with victory at Loftus Road.

Manager Louis van Gaal heard the first sounds of revolt from United fans towards the end of a dismal first half when they called for him to ditch his favoured 5-3-2 formation.

Van Gaal responded by introducing Marouane Fellaini for Juan Mata at the start of the second half and the giant Belgian answered the call by putting United ahead with an emphatic finish.

The goal was harsh on QPR after England prospect Charlie Austin - watched from the directors' box by manager Roy Hodgson - twice brought fine saves out of United keeper David de Gea before the interval.

United's confidence increased with that goal and with QPR pressing in desperation for an equaliser, substitute James Wilson secured the three points with the second on the break in the dying seconds.

It was the perfect response by United, although recalled striker Radamel Falcao failed to score, twice being thwarted by QPR keeper Robert Green.

The pre-match talk had been that Redknapp's job at QPR would be in jeopardy if they lost, but this was not the performance of a team that had lost belief in its manager. Results, however, are all and this defeat keeps QPR firmly in the relegation zone.

Falcao's future has also been the subject of debate this week after Van Gaal left him out of the squad for the loss against Southampton - but the Colombian striker was back here and wasted an early chance to impress his manager.

He made space in the area to collect Mata's pass but could only shoot straight at QPR keeper Green from eight yards.

Austin has taken on the role of QPR's main hope of salvation this season - and he accepted that responsibility by bringing the best out of De Gea with two right-foot volleys showing good technique and accuracy.

With the interval approaching there was unrest among United's followers, with chants of "4-4-2" and "attack, attack, attack" in the face of a performance lacking any creativity.

Van Gaal acted and removed Mata to introduce Fellaini at the start of the second half, also reverting to a more orthodox back four.

Their play immediately carried greater threat and it took a brilliant flying save from Green to turn away Falcao's header when he seemed certain to nod in Angel Di Maria's cross.

It was not long before United were ahead as Van Gaal's decision to bring on Fellaini brought the perfect reward, the Belgian powering home his finish after Antonio Valencia had been played in by Wayne Rooney's clever pass.

QPR's threat had diminished but a breakdown in communication between Michael Carrick and Marcos Rojo on the halfway line presented them with an opportunity that was wasted by Eduardo Vargas. The United pair left each other to it, allowing Vargas to race clear but he refused to pass to the unmarked Austin and was crowded out.

Falcao continued to strive in vain for that elusive goal, first being denied by Steven Caulker's slight touch and then just failing to connect with another Wilson cross.

And it was Wilson who struck the final blow to deflate QPR and leave United buoyant once more.

QPR boss Harry Redknapp on speculation surrounding his position:

"It was one reporter saying it and all of a sudden it became gospel.

"I've never been at a club quite like it in my life but someone has made a bit of money out of it.

"All the speculation was that I was going to lose my job if we lost this game. I spoke to (owner) Tony Fernandes this week and he certainly never said anything like that to me.

"If we can get another striker in on loan then we'll stay up no problem."

Manchester United boss Louis van Gaal:

"I know in advance that when we play with four midfielders in a diamond that we create more chances, but then the balance of the team is also weak.

"And you've seen it because we had created chances but so had QPR.

"We have to decide every week how we have to play. And that's the question.

(On the form of David de Gea) "I think he's been playing well all this season. We have a lot of clean sheets and that is mainly down to him."

Falcao returned to United's starting XI after being left out for tactical reasons in last week's defeat by Southampton

Harry Redknapp denied claims his job would be under threat if they lost the match

England boss Roy Hodgson was in attendance at Loftus Road to see captain Wayne Rooney and QPR's 13-goal striker Charlie Austin

James Wilson cam one as a second half substitute for Jonny Evans