Christopher Samba fouled Ashkan Dejagah to concede an early penalty, which was converted by Dimitar Berbatov, before being caught in possession to allow the striker to add his second. A Clint Hill own goal saw QPR fall 3-0 down before Adel Taarabt pulled a goal back, and Loic Remy netted a second after he had seen a penalty saved by Mark Schwarzer.
"We started sloppy," Redknapp said. "We gave an early goal away and suddenly you're on the back foot, you can't give goals away like that and win football matches. They were the worst three goals you could ever wish to see given away."
Redknapp felt the game was there for the taking, especially after Fulham midfielder Steven Sidwell was sent off for a challenge on Armand Traore, but the former Tottenham boss was left bemoaning the poor opening to the match.
He added: "They didn't have to work for their goals, the penalty we got caught in possession, then we lost the ball and then with the own goal - you couldn't have seen three worse goals.
"We did well to come back from there and in the second half we deserved to get something out of the game - we battered them second half. At 3-2 I could see only one winner."
Samba, who joined from Russian outfit Anzhi Makhachkala for a club-record fee to much fanfare in the January transfer window, had an off night and Redknapp said it was not a performance you would normally associate with the former Blackburn defender.
Samba pushed up late on in the search for a dramatic equaliser, much to the chagrin of his manager.
"It is not like him, he is normally a very confident guy," Redknapp said. "He got caught with the ball and it cost us dearly. When they had 10 men and we are murdering them with 11 you have got to play.
"I don't want to start lumping it into the box to Samba, (Bobby) Zamora or Remy. You have got to play and use that extra man. We had been creating three or four chances every 10 minutes and with 10 men we would have created even more chances."
- Sports & Recreation