Robin van Persie inevitably found the next against Arsenal in his first meeting with the Gunners since leaving the club, as Manchester United claimed a comfortable victory at Old Trafford.
It was the first time Arsenal had been away to Manchester United since last season's 8-2 drubbing, and a similar scoreline looked achievable when they went 1-0 behind in two-and-a-half minutes.
Van Persie scored the opener, while Wayne Rooney missed a penalty before half-time, while Patrice Evra doubled United's advantage shortly after the hour mark.
Jack Wilshere was sent off for Arsenal in the second period, while Anderson had a late goal ruled out for offside, before Santi Cazorla netted a late consolation from 18-yards.
Van Persie took less than three minutes to turn the screw on his former club following his summer transfer, with the Dutchman making the most of a Vermaelen mistake.
Vermaelen, who succeeded Van Persie as Arsenal captain, got his feet in a muddle when trying to clear his lines, and Manchester United's No.20 fired neatly first-time past Vito Mannone with his right-foot.
Arsenal could hardly muster an effort on goal in the first period, and were lucky to repel a to enter into the break only one goal behind.
Rooney had the opportunity to double the advantage moments before the half-time interval after a Cazorla hand ball and provided Manchester United with a penalty.
But the 27-year-old failed to find the target from the spot; firing wide of Vito Mannone's left-hand post to hand Arsenal a reprieve when he could have struck a significant blow.
Van Persie almost made up for Rooney's error mere seconds after half-time but he was unable to find the net for a second time, and his miss sparked Arsenal into life.
Giroud hit the post as the Gunners began to play with more confidence and flair, with Wilshere and Cazorla beginning to have a greater influence on proceedings.
But, just as Arsenal began to look dangerous, Evra stole in at the back post to beat Vermaelen to the ball and head Manchester United into a two-goal lead.
Arsenal's misery was compounded when Wilshere saw red for a deserved second yellow card on only his second appearance in the Premier League in 18 months, which extinguished any minscule hopes of a Gunners comeback.
Cazorla did ensure United failed to keep a clean sheet once again when he fired into the top corner from the edge of the box, but the Spaniard did so with the virtually the last kick of the game.
Three points took Manchester United top of the Premier League table, with Chelsea not scheduled to play until this afternoon, while Arsenal are now nine points behind the leaders.