Sir Alex Ferguson rounded on Arsenal captain William Gallas after Manchester United secured their place in the quarter-finals of the FA Cup.

The Old Trafford boss felt Gallas deserved to be red-carded by referee Alan Wiley for a challenge on Nani in the second half.

Ferguson said: "I thought Gallas should have been sent off. The referee must have a look at that again.

"He kicked Nani from behind and the referee called both over because they sized each other up. He should have been red-carded."

Arsenal manager Arsene Wenger claimed he had not seen the challenge by Gallas on Nani and suggested the United player showed a lack of respect by showboating.

Wenger said: "Nani was very good today but he did not need to juggle the ball.

"He is a young player and wanted to show what he could do. Maybe he can learn from this."

Ferguson agreed. "I think he shouldn't be doing that, he doesn't need to do that," he said.

"In some ways it shows a great deal of courage to do what he did, that's one side of it."

Ferguson felt the drubbing of Arsenal was the perfect response to last week's Manchester derby defeat in the Barclays Premier League.

The pick of the fifth round was expected to be a close affair but United were 3-0 up by half-time thanks to goals from Wayne Rooney, Darren Fletcher and Nani.

Fletcher marked his first start in two minutes by rounding off the victory with his second goal after 74 minutes - after Arsenal's Emmanuel Eboue had been sent off.

Ferguson said: "It was a really fantastic performance. The players looked great. They showed tenacity and the passing was terrific.

"They were so disappointed with themselves (after losing 2-1 to Manchester City) on a really important day. I think all the emotions of the week probably caught up with them.

"But today they've made amends for that with a marvellous performance."

United ran the midfield, and Ferguson reserved particular praise for Fletcher, who has had little opportunity to shine this season.

"Darren Fletcher is one of these players who always plays well against Arsenal," he said.

"I think he's had two man of the matches in semi-finals. Sometimes it's horses for courses and I think it was Darren's day.

"Some of the passing was very good and the running off the ball was very good. It was a great performance by us."

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