Ryan Yates then put the home side ahead with seven minutes to go, reacting quickest from a corner, before Brennan Johnson completed the scoring shortly after.

The result sees QPR drop down to sixth while Forest move up to eighth, one point behind the visitors with a game in hand after extending their unbeaten run in all competitions to nine matches.

After thumping Reading 4-0 in their previous match, in-form Forest had only lost twice in their previous 32 home league fixtures against QPR.

It was the visitors who were left wondering how they did not take an early lead, however, when Luke Amos and Lee Wallace both failed to tap in a cross from Gray.

Forest gradually took control on the attack and Yates saw two clear chances go begging from close range, forcing a good save from David Marshall and then missing the target.

Yet it was Gray who found the back of the net against the run of play, with his third goal in three matches following a well-worked assist from substitute Ilias Chair.

Spence caused problems for QPR whenever he stepped up to the ball and he deservedly brought Steve Cooper's side level with a curling shot over and behind Marshall.

He twice teed up Keinan Davis, who should have scored, while Philip Zinckernagel forced a save out of Marshall - who was kept increasingly busy.

QPR boss Mark Warburton had used all three substitutes when Marshall pulled his hamstring with 18 minutes still left and, while the Scot dutifully carried on, the injury eventually caught up with him.

Yates side-footed in from a set-piece to put Forest in front and, while Marshall did well to deny Cafu minutes later, he could not stop Johnson's shot to seal victory. He then hobbled off and QPR saw out the match with defender Wallace in goal.

Nottingham Forest manager Steve Cooper said:

"They were a bit better than us for the first 10 minutes, but we were good after that and looked like we were going to take the lead after a couple of near misses.

"Then, they scored against the run of play and that can derail you when you are playing well but, in the second half, we were brilliant.

"It took a brilliant goal from Djed to level the scores and sometimes you need something special to start things off but, in the end, they could not live with us and they are a team that have been in the top six for most of the season so, to run over them the way we did, meant we were really good for the win.

"We've scored seven goals in two games now and that's what the supporters want to see and what I want them to see."

QPR manager Mark Warburton told BBC Radio London:

"I thought the goal was excellent, the way we crafted the goal. Got that one down the side and we missed a huge chance. Great to see our midfielders bursting into the box, but we've got to score. We're three or four yards out to an open goal, you've got to score.

"They're the fine margins, going 2-0 up and that game is a different game completely.

"But at 1-0 we were good, to the hour mark we were good, the guy scores a 30-yard screamer - I'm not sure any keeper saves that kind of shot and this place comes alive.

"But still deal with it, OK they're on top, they had good energy and the home crowd behind them but we were OK. But as I say the set-piece really hurt us. We can't give away a set piece goal of that nature."