SIR Alex Ferguson said Wanderers could do nothing to prevent his side romping to a sixth successive defeat of their Greater Manchester neighbours at Old Trafford on Saturday.

While Sam Allardyce blamed his own team's shortcomings for the margin of victory, Ferguson said United deserved all the credit.

"We have played some of our best football of the season against Bolton," the United boss said.

"Bolton have worked hard. But what worried them was the quality of our goals. The combination between Ronaldo and Rooney for the second was absolutely magnificent.

"It was a really top performance and Bolton could not do anything about it."

The only downside for United - and the watching Steve McClaren - was the seventh minute injury that forced skipper Gary Neville to limp out of the game and out of England's European Championship qualifiers against Israel and Andorra.

Ferguson confirmed that Neville would be out for at least three weeks with ankle ligament damage but praised Wes Brown for his performance and confirmed he would stay at right back for tonight's FA Cup quarter-final replay at home to Middlesbrough.

"Even when Gary Neville got his injury and there was a hush in the crowd, the players were undeterred," the United manager said. "The performances of Ferdinand and Vidic laid the foundation for us and enabled Wes Brown to settle in. He ended up having a marvellous game himself.

"Initially, people thought not another injury' but the resilience of this team means they are not going to be put back at all."

Ferguson is urging Saturday's star man, Cristiano Ronaldo, and his agent to ignore overtures from Spain and continue talks that will eventually lead to an extension of his United contract.

Speculation is rife that the 22-year-old Portuguese international, whose breathtaking first half display laid the foundation for United's crushing defeat of Wanderers, is the target for bank-breaking bids by Real Madrid and Barcelona.

But Ferguson hopes to counter any rival offer and ensure that his brightest star, widely regarded as the best player in the world, will commit his future to the Reds.

"There's going to be speculation," Ferguson said, "The elections in Spain with Real Madrid and Barcelona mean they do this all the time.

"It's unfortunate that there's been some stuff coming from Ronaldo's agent. I just hope his agent allows us to go on with negotiations. He too should be part of that."

Ronaldo had a hand in the three goals that effectively sealed victory for United inside just 25 minutes of Saturday's Old Trafford derby.