The Northern Ireland international handed Steve Clarke's side a first-half lead at Loftus Road with a sublime left-foot shot from 30 yards.
It was only his second goal of the campaign and he is happy to concede that he should have had far more to his name by now.
He told his club's official website: "It has been a frustrating season for me as I have been in and out of the team with injuries.
"I have had a few games recently, but a goal has been a long time coming and I am delighted to have got one.
"The gaffer had a bit of a joke with me the other day about me not scoring enough goals, but I knew he meant it.
"I try to get shots on target from outside the box and I knew as soon as I had hit it that I had hit it well enough for it to go in.
"Obviously, getting the three points is the main thing, but I am pleased I got a goal."
A Rob Green own-goal doubled West Brom's lead against QPR and while Djibril Cisse pulled one back, the visitors hung on for a second victory in a row.
It moved them up to sixth in the Premier League, level on points with fourth-placed Tottenham Hotspur and fifth-placed Everton.
Brunt added: "We went off track a little bit with three successive defeats, but now we are unbeaten in three and we have won our last two.
"It is very important in this league to pick up back-to-back wins."
Brunt revealed hard work was the key to resisting QPR's fightback.
He said: "Any Premier League side is going to cause you problems when they are trailing at home and they threw everything at us in the last 20 minutes.
"But we battled away, as we have done all season, and managed to hold on for the win.
"We showed that we are a good bunch of lads that work hard for each other week in, week out."