Neil Warnock was furious after Cardiff City’s fourth successive Championship defeat.
The Bluebirds manager believes Junior Hoilett had a perfectly good equalised ruled out for offside after referee Tim Robinson and a linesman spent a minute consulting.
Warnock said QPR midfield player Josh Scowen played the ball which would mean Hoilett was onside.
“The referee is in a good position,” said the Cardiff manager. “He thinks the ball was deflected and clearly it’s Scowen who has played the ball – so Hoilett can’t be offside.
“It’s hard enough for us to score goals without having officials chalk them off wrongly, it’s very deflating and I thought he missed a penalty in the first 14 minutes.
“It’s scandalous at the moment. I’ve never known it as poor, the officials, at the moment.”
QPR twice hit posts after falling 1-0 behind, while manager Ian Holloway was elated after the win.
Paul Smyth, signed from Linfield last summer, was in excellent form and created a couple of chances before scoring the winner. He went past Cardiff central-defender Bruno Manga and firing home.
That made 20-year-old Smyth popular among home fans, although Cardiff had the chances to have earned a point.
Rangers manager Ian Holloway admitted selecting Northern Ireland-born Smyth for his debut was a gamble, saying: “It was probably one of the biggest risks I’ve ever taken.
“It could have gone horribly wrong, but it didn’t. He was a breath of fresh air.
“I thought their centre-backs might have problems with him. It was just about how he was going to handle it.
“Sometimes you need that bit of freshness. We are reshaping the tree of QPR.”
The next test for Cardiff City is at home against Mansfield Town in the FA Cup third round next Saturday.