Sir Alex Ferguson launched into his Manchester United defence after they let Louis Saha give them an almighty scare at Old Trafford.
The United boss was delighted with Ruud van Nistelrooy's double strike, but had some stining criticism for his back four as they were breached at the start of each half.
He told Sky Sports: "There's casualness about the defending which I hope will improve as the weeks go on.
"We need to get an edge to our defending - I would expect us to last more than four minutes before conceding a goal."
Luckily for United, their sloppiness at one end of the pitch was matched by a sharpnesss at the other and Fergie was left drooling by van Nistelrooy's opening goal that levelled the game at 2-2.
He said: "His first goal was absolutely superb, out of nothing. It was a goalscorer's goal which I think won the game for us.
"I thought Fulham gave us a lot of problems. We did a lot of good things but there wasn't the flow of the game we expect."
Cottagers chief Jean Tigana admitted that his side had learned a harsh lesson about life in the Premiership after leading twice only to be toppled 3-2.
Although he seemed happy with his side's efforts, he warned his players that they will have to bounce back from the defeat and improve at both ends of the field.
He said: "For us today is a good lesson because we need to score more and defend well. It's possible to play at this level but we need to score when we have the chances and to progress together.
"I am never pleased when I lose. Our next two games are important. My players are very tired today - we need a good recovery."
Sean Davis admitted that Fulham were made to pay for lapses in concentration, but still insisted the performance at Old Trafford will send them into their next Premiership clash in good heart.
The England Under-21 midfielder set up the first for Saha, but was harshly penalised for the free-kick that saw David Beckham level the scores to set up United's second-half comeback.
He said "We came out firing in the second half. Unfortunately we gave away a couple of goals. We defended well today - except for that lackadaisical spell.
"We've come to the best team in the country and we've created a few chances. We could have gone in at half-time 3-0 up. Well go into the game against Sunderland (on Wednesday) full of confidence and hope to give the fans a win."
Two-goal hero Louis Saha was equally upbeat despite seeing his double overshadowed by Ruud van Nistelrooy.
He said: "It was a very hard game - but I think we played well today. It's like a dream to score against Fabien Barthez because he's one of the best keepers in the world. It was a pleasure.
"We've showed all over the pitch we play good football."