David Beckham called Wayne Rooney one of the world's best footballers as Manchester United put his AC Milan side out of the Champions League.

Rooney scored twice as United romped to a 4-0 last-16 second-leg win tonight to secure a 7-2 aggregate victory and a place in the quarter-finals as Beckham's return to Old Trafford ended in defeat.

"He's such an exceptional talent," Beckham told ITV1 of Rooney.

"I think without a doubt he's one of the best, if not the best, player at the moment along with (Cristiano) Ronaldo and (Lionel) Messi."

Beckham entered the fray midway through the second-half, coming off the substitutes' bench to a standing ovation.

But the contest was already over.

"It was a disappointing night because we lost the game but returning here is always special," added the former England captain.

"It was unbelievable. I have to say thank you. It was really incredible.

"It was nice to be back, a disappointing night but nice to be back."

Rooney has now scored 30 goals this season and could overtake the tally of 42 achieved by Ronaldo - now at eliminated Real Madrid - in the 2007-2008 season.

"It's a challenge," United manager Sir Alex Ferguson told ITV1. "I was happy with him getting to the 30 mark, to be honest.

"But he just keeps improving and tonight he was sensational."

Milan simply could not live with United, Ferguson said.

"It was a marvellous second-half performance," he added. "We played very, very well.

"When we play at that tempo, we're difficult to play against and it was a really solid performance."

Ferguson believes United are now capable of going all the way in the tournament and is happy to play anyone in the last eight.

"With that kind of team I've got it doesn't matter who we play," he said.