Substitute Grant Holt made an immediate impact to give Norwich all three points at Carrow Road.
The home side had taken the lead when Russell Martin fired in a loose ball from the edge of the six-yard box.
QPR responded well after the break and levelled when Luke Young slotted home a rebound after Jamie Mackie's low drive had come back off a post.
But Holt was on hand to bundle home from inside the six-yard box after a cross from another sub, Wes Hoolahan.
The two promoted sides, enjoying comfortable mid-table positions in the top flight, served up an attractive encounter which may have been short of quality in front of goal but was finely balanced throughout and had its only yellow card in the final five minutes.
Not long after kick-off, Anton Ferdinand, under pressure from Steve Morison, headed weakly back to former Spurs goalkeeper Radek Cerny, who was deputising for the injured Paddy Kenny.
But, having seized possession, the Norwich striker's left-footed effort was smothered by the Czech.
However, the home side were soon in front as Andrew Surman's left-wing corner fell invitingly for Martin to hook home.
QPR looked comfortable in possession but struggled to break down the Norwich defence, although Shaun Wright-Phillips collected Heidar Helguson's flick-on before tumbling under the challenge of advancing keeper John Ruddy, referee Mark Clattenburg well-placed to decide no illegal contact had been made.
Wright-Phillips freed Young down the right flank and his cross found Helguson at the back post, but the veteran Icelandic striker's header was as weak as the moustache he is growing for the admirable Movember men's health awareness campaign.
In the closing moments of the opening period the visitors finally began to threaten, a Wright-Phillips free-kick drifting through a crowd of players with Shaun Derry unable to get the touch required at the far post.
Wright-Phillips then ghosted through and tested Ruddy with a low shot from 16 yards, Mackie firing the rebound into the side netting from a narrow angle.
The visitors started strongly after the break and Norwich continued their unfortunate trait of failing to keep a clean sheet this season.
Mackie ran purposefully at the defence and his shot from 20 yards rebounded perfectly off the left-hand upright for galloping full-back Young to side-foot in from 10 yards, his second goal in as many games.
However a double change injected some impetus into the home side and, within three minutes, both new additions had inspired the winner.
Holt, who moments earlier had seen a header from Morison's delicate cross cleared off the line by Derry, forced the ball into the net following a teasing left-footed cross from Hoolahan on the right-hand side.
Still the chances continued for Rangers, Young's cross from the right clipping the top of the bar and Helguson heading over, but Norwich held on to move above the Hoops into ninth place.
Norwich manager Paul Lambert:
"Any game is vital but I think we deserved the win.
"They put us on the back foot after their goal but I think in general terms we were excellent and I'm delighted with the win."
QPR boss Neil Warnock:
"I can't believe we haven't won the game.
"We played some great football but the two goals we conceded were like Sunday League goals.
"Norwich took their opportunities but when we got the equaliser we should have gone on to win the game."