Ryan Giggs's first match as Manchester United's interim manager ended in a 4-0 Premier League thrashing of Norwich City at Old Trafford on Saturday.

Wayne Rooney and substitute Juan Mata scored two goals apiece as the faltering English champions, still a relatively lowly seventh in the table, proved too strong for the struggling Canaries.

Giggs saw Rooney give United the lead with a 41st-minute penalty after Danny Welbeck went down in the box.

England striker Rooney made it 2-0 seven minutes after the break with a curling shot from outside the box as Norwich's defence backed off.

Mata put the result beyond doubt in the 63rd minute when he turned in Phil Jones's cross before adding a second goal 10 minutes later as Norwich retreated again.

United great Giggs, previously a player-coach, was put in caretaker charge for United's final four games of the season after David Moyes was sacked on Tuesday.

Moyes was dismissed just 10 months since replacing the retired Alex Ferguson after a 2-0 defeat by Everton made it mathematically impossible for United to qualify for next season's Champions League.

The 40-year-old Giggs, English football's most decorated player, resisted naming himself in either the starting line-up or on the bench against Norwich.