ROOKIE manager Ryan Giggs last night gave the Manchester United board food for thought as he enjoyed a dream dugout debut at Old Trafford.

Wayne Rooney and Juan Mata both scored twice as Giggs oversaw a comfortable 4-0 win over Norwich.

Giggs assumed temporary control of United on Tuesday following the sacking of David Moyes.

Although the United board are searching for an experienced successor, Giggs has made no secret of his desire to become full-time manager.

And the 40-year-old interim manager did his chances no harm with this display. Once United had put a slightly cumbersome first half behind them, they strolled to victory.

What is more, they did it with the style and panache that has been missing from the men in red for most of the season.

Wayne Rooney got the bandwagon rolling when he fired home a first half penalty after Steven Whittaker had tugged back Danny Welbeck.Less than three minutes after the restart, United were 2-0 up thanks to some inept defending from Norwich.

Four defenders failed to challenge Rooney, who, despite slipping, curled a right-footed shot past John Ruddy and into the net off the far post.

Ruddy fumed at his defenders for backing off. Moments later he was at full stretch to deny Welbeck as United upped the pressure. Sir Alex Ferguson and many more United fans got to their feet to clap Welbeck off on the hour as he was replaced by Mata.

Three minutes later Mata found the net as he turned home Jones' cross from close-range. Soon after the Spaniard had his second after he nodded home Antonio Valencia's shot from close range.

Rooney was full of praise for Giggs' impact on the team since taking charge, although he stopped short of saying he should be the next United boss.

"Giggsy is a really experienced player and he's built to be a manager," he said. "He has all the credentials to be the next boss but that decision is down to the board."