United will resume their last-16 tie against Madrid on Tuesday following a 1-1 draw in the away leg and Kagawa’s first United treble ensured they will approach the game brimming with confidence.
Ryan Giggs was made to wait for his 1,000th appearance after being left out of United’s match-day squad, but manager Alex Ferguson selected his first-choice strike pairing of Robin van Persie and Wayne Rooney.
The hosts dominated the first half at Old Trafford but they had to wait until first-half stoppage time to take the lead. Japan international Kagawa claimed the goal, beating Norwich goalkeeper Mark Bunn with a near-post volley after van Persie had helped on Antonio Valencia’s inswinging right-wing cross.
Kagawa doubled United’s tally 14 minutes from time, sweeping home from Rooney’s square pass, and completed his treble in the 87th minute by racing onto a Rooney lay-off and coolly lifting the ball over Bunn.
Rooney got on the score-sheet in the final minute with a beautiful strike into the top-left corner from outside the box to further amplify the task facing second-place Manchester City, who visit Aston Villa on Monday.