United scored three times in the first six minutes of a fifth round replay at the Madejski Stadium on Tuesday and eventually edged into the quarterfinals with a 3-2 victory.

Ferguson's team, who will visit Middlesbrough in the quarterfinals on March 10, went ahead through Gabriel Heinze's second minute strike before Louis Saha and Ole Gunnar Solskjaer increased the lead in a frantic opening.

However, Reading recovered to mount a marvellous fightback with goals from Dave Kitson and substitute Leroy Lita and they nearly got an equaliser when Brynjar Gunnarsson hit the crossbar in the last minute, leaving Ferguson to admit he had never seen anything like it.

Ferguson said: "I think it was a fantastic cup tie and credit to both sides, anyone turning up to watch that game would not have left disappointed.

"It was the best ever start I have seen and three goals in six minutes was magnificent but sometimes that can be a problem. We gave them a goal after 20-odd minutes and that gave them a lifeline.

"In the first half we played the ball in behind them so much they did not seem to know how to deal with it but in the second we started playing across them which was not as successful.

"The way Reading play, they are a team who like to cross the ball and they are very good at it. It gave us a really hard test.

"As the clock was ticking down I was thinking to myself I would have to prepare for extra time and I told Paul Scholes to get ready.

"That was how I thought the game was going but we held on and the main thing is we are in the next round."

Despite their dream start, United's goals owed as much to Reading's defensive mistakes as it did to the visitors' ruthlessness in front of goal.

Heinze's long ranger should have been gathered by Reading goalkeeper Adam Federici but the Australian, who was named player of the Fifth Round earlier in the week, allowed it to squirm under him and roll over the line.

Saha's second was a cracking strike from what seemed a largely unthreatening angle but Andre Bikey's reluctance to close the Frenchman down gave him the chance to pick his spot.

And the Royals failed to learn their lesson for United's crucial third as they allowed Solskjaer a clear 50-yard run on goal, forcing Steve Coppell to admit he perhaps got his early match tactics horribly wrong.

Coppell said: "I wanted to keep things tight early on and after the start we had I would question myself and maybe we should have gone gung-ho from the first whistle.

"It made me sink into my seat a little but we got ourselves back into the game and I could not question my players' efforts.

"They worked and grafted and tried to create chances and we came very close to sending it into extra time.

"I could not blame our goalkeeper because he made some good saves and some great interventions from crosses. I am not prepared to blame anybody and I have only praise for my players."

Coppell insisted Reading's fightback showed exactly why they have made such a good impression in the Premiership this season.

He added: "It is not often you say there can be honour in defeat but that is the position we are in tonight. I have to compliment my players. They are all warriors.

"They didn't lay down and die, they got back up again and fought, which is one of the best qualities to have."