Davis was fuming with his players after they allowed QPR to get on top in the first half and take the lead through a Paul Furlong header.
Preston hit back in the second half through sub David Nugent and Lucketti, but it didn't save the players from Davies' criticism.
Davies said: "We were very poor in the first half and we let down the fans with that performance.
"QPR deserved to be ahead and there were one or two choice words at half time. There were just a lot of disappointing performances.
"I am very pleased with the three points but we are not getting ahead of ourselves. There are a lot of points we can improve on and we are a mile away from being the finished article.
"I keep saying to the players there is nothing to celebrate now. We can look back at the end of the season."
Preston came into the game on the back of an impressive haul of 20 points from their last eight games, but they showed little sign of the form from the kick off.
Keeper Andy Lonergan had to be at his very best to deny Jamie Cureton from close range on four minutes and was saved by the woodwork six minutes later.
A long punt from Simon Royce was feebly headed back by Youl Mawene and Cureton took advantage to flick the ball over Lonergan only to see it clip the top of the bar.
Preston hit back briefly to show they were up for the fight only to see top scorer Richard Cresswell fail to take two good chances.
He combined well with Patrick Agyemang in the area but drove his shot tamely wide and then saw his flicked header drift past the post.
But the home side were clearly on top and took the lead when Lee Cook sent in a fine cross for Furlong to head his 15th goal of the season.
Preston boss Davies hauled off the ineffective Agyemang and Dickson Etuhu to put on Nugent and Paul McKenna and it almost paid instant dividends.
Cresswell played in Nugent and he was only denied by a fine save from Royce.
Chris Sedgwick then sent a curler just past the post and it was no surprise when Preston levelled the scores.
McKenna's shot was too hot to handle for Royce and Nugent was the first to react to put it in the net.
On 75 minutes QPR failed to clear a Sedgwick cross and Lucketti made no mistake from close range.
The win was soured when Eddie Lewis picked up two yellow cards in three minutes late on and was shown the red card, but it was too late for Rangers.