Wayne Rooney scored a hat-trick as Manchester United pummelled Arsenal.
Danny Welbeck, who was later injured, headed in Anderson's pass and Robin van Persie's penalty was saved by David De Gea before Ashley Young struck.
Wayne Rooney put United out of sight with two superb free-kicks before scoring from the spot late on.
Nani, Park Ji-sung and Young added further goals with Theo Walcott and Van Persie replying as Carl Jenkinson was sent off on 77 minutes.
The Arsenal right-back's second booking means that Arsenal have had a man sent off in each of their opening three Premier League games.
And it compounded a miserable afternoon for the Gunners, who could have been beaten by an even greater margin, such was the hosts' dominance.
The only sour note was a hamstring injury to Welbeck, who looks likely to be withdrawn from the England U-21 squad for their Euro 2012 qualifier on Thursday.
But it was the perfect response to their neighbours - Manchester City - who earlier beat Tottenham 5-1 at White Hart Lane, and the victory lifted United to the top of the Premier League table.
http://news.bbc.co.uk/sport2/hi/football/14606020.stm
