QPR manager Mark Warburton defended Joe Lumley after the goalkeeper's error meant they had to hold off a fightback from Luton before securing a 3-2 win.
Nahki Wells scored twice as the west London side raced into a three-goal lead within 28 minutes at the Kiyan Prince Foundation Stadium, where Ebere Eze also scored and was twice denied by the woodwork.
However, Luton were gifted a way back into the game when Lumley inexplicably played the ball straight to Harry Cornick, who helped himself to a goal nine minutes before half-time.
James Collins pulled another back for the Hatters early in the second half but QPR held on for a third successive league win.
Warburton is keen for his keeper to play the ball out from the back and refused to criticise Lumley, who made a mess of an attempted pass to Ryan Manning.
Warburton said: "As a team we gave a soft goal away. We're all human and we all make mistakes. That happens.
"To give them a glimmer of hope like that, we shot ourselves in the foot. Then they scored early in the second half and suddenly the whole dynamic of the game changes.
"You can't say to someone 'Be brave, get on the ball and play from the back – don't make a mistake!' You can't do that. We're all humans, otherwise we'd be machines.
"We made a mistake. How do we respond? I want the team not be reckless, but to be brave and get on the ball and when we do that we look a good team."
Rangers' nerves were not helped by Jordan Hugill missing two glorious chances to extend their lead in the second half.
Warburton said: "We were very good in that first half an hour. We hit the bar twice and put two wide, so it could have been a lot more in that first half.
"We still missed chances in the second half and we've got to be more ruthless in front of goal because goals change games.
"We've got to recognise that. But we got three points, really important, and three wins on the spin."
Luton manager Graeme Jones has no doubt his promoted side will learn from their appalling start to the match.
"We took a few risks and could easily have got something from the game. It was a mountain to climb at 3-0 down," said Jones.
"Sometimes you win and sometimes you learn. Today I'm afraid it's time to learn. It's a learning curve. We started a little bit sluggish and naive.
"We'll look at it and we'll analyse ourselves. We'll face it. Sometimes it's tough but we will learn from it, I assure you of that.
"Sometimes you have to take it on the chin. Nobody said coming into the Championship was going to be easy.
"I've seen teams fold at that point – 3-0 down. But we took them to the last second of the game. We're learning and have done very well.
"But today we're losers and I don't like that. I let one or two know I didn't like what I saw in the first half. We need to learn and we need to improve and I am sure we will."