Premier League: Queens Park Rangers 0 Manchester United 2
United full-back Rafael struck a stunning half-volley into the top corner from 25 yards to put his side ahead in the 23rd minute at Loftus Road on Saturday.
Ryan Giggs sealed the points for the league leaders 10 minutes from time as he beat the offside trap to sweep the ball home.
The only concern for United will be a suspected back injury to top scorer Robin van Persie, who came off five minutes before half-time after a collision on the touchline.
The result leaves United with a 15-point advantage over Manchester City before Roberto Mancini's men take on Chelsea on Sunday.
QPR remain rock bottom in the Premier League and look destined for the drop.
After a tepid start to the game, United took the lead in the 23rd minute.
Julio Cesar parried away van Persie's initial cross-cum-shot and the ball fell for Rafael to crack an outstanding half-volley into the top corner from 25 yards.
At the other end, Rafael was on hand to deny QPR an equaliser as he cleared Christopher Samba's header off the line from Esteban Granero's corner.
United immediately counter-attacked and a swift move ended with Cesar producing a fingertip save to keep out van Persie's cushioned volley after the Dutchman latched onto a cross from Rafael.
It was van Persie's last real involvement as he was substituted five minutes before the break with a back injury he appeared to pick up in an innocuous collision with a photographer in the build-up to United's opener.
QPR substitute Loic Remy almost made an immediate impact when he cut in from the left and saw his powerful near-post shot saved by David de Gea in the United goal.
As QPR attacked, the game opened up for United on the counter-attack and Sir Alex Ferguson's side took advantage 10 minutes from time.
Nani played in Giggs and the 39-year-old used all of his experience to beat the offside trap and slot his finish past Cesar.
Moments later, Giggs nearly scored a second but his mishit shot skied into the air and inadvertently hit the crossbar.
By then the result was beyond doubt as United continue what appears to be a stroll towards the title.