QPR manager Mark Warburton was angered by the lapses in concentration which led to two penalties being conceded against Preston.
Rangers were beaten 2-0 at the Kiyan Prince Foundation Stadium, where both spot-kicks were given away by Lee Wallace.
Scott Sinclair was surrounded by Rangers players before being tripped for the first.
And Emil Riis Jakobsen was brought down by Wallace after getting in front of Rob Dickie.
“After the first 20 minutes I thought we were in control of the game,” Warburton said.
“After 20 minutes I’m thinking ‘if we score now the game’s over’.
“What was really disappointing was that we gave a really soft penalty away and then didn’t respond well to it.
“It was like the wind was out of our sails, our shoulders dropped and we looked a very average team. We stopped doing what we were doing.
“We had five men around him for the first penalty. He shouldn’t even have got in our area. We should just confront him outside our area.
“Then we let in another soft goal. Just head the ball away – but we let it bounce and the guy’s very clever and leaves his leg and goes over. It was an awful second goal.
“We have to learn because the reaction was poor after a really good start.
“We were in control against a good team and let that strong start slip.”
On a brighter note, Warburton suggested that Lyndon Dykes is likely to return for Saturday’s game at home to Birmingham.
The Scotland striker has missed two games because of a thigh problem and Rangers have failed to score in both.
“This was probably just a couple of days too early for Lyndon,” Warburton said.