Cristiano Ronaldo surpassed 800 goals for club and country with a double as Manchester United beat Arsenal 3-2 to close to within three points of the Premier League top four.
With new interim manager Ralf Rangnick watching from the stands, the German was given a glimpse of both the talent he will have to work with and problems he has to solve at Old Trafford.
Ronaldo's 800th career goal was quickly cancelled out by Martin Odegaard.
But the five-time Ballon d'Or winner had the final say when he crashed home a penalty 20 minutes from time.
A vital victory for United cuts the gap between the sides to two points in the battle for a place in next season's Champions League.