In mid-March Arsenal were three points behind United with a game in hand and had real belief that they could win the league for the first time since 2004.
With four games remaining for both, Arsenal trail the leaders by nine points and are also three behind second-placed Chelsea.
With Chelsea facing a tough home game against fifth-placed Tottenham Hotspur on Saturday, United could potentially end the weekend with the title all-but wrapped up before they host Chelsea next Sunday for a timely changing of the guard.
Even if Chelsea beat Spurs, wins over their two main rivals for United would secure their record 19th English championship with two games to spare.
With United playing Schalke 04 in the second leg of their Champions League semi-final on Wednesday it is a huge week for Sir Alex Ferguson's team - and all achieved by a side we are constantly told is "not vintage."
"People can have those opinions and keep talking like that. We just try to win games," said centre-back Rio Ferdinand. "If we win games and end up winning titles we won't be thinking about what people have said about us.
"What sets us apart from other teams is that the hunger never dies. It stems from the manager and filters down.
"We have players who want to win things. There are still players in this squad who have not won the league. There are others who have won it a few times who want more. That is the basis on which we do our work every single day."
KILLER INSTINCT
That killer instinct was on show last week when, against an in-form Everton, United kept fighting, pressing and throwing men forward until they finally got their decisive goal six minutes from time.
The next day Arsenal conceded a stoppage-time goal to lose 2-1 at Bolton Wanderers to cap an horrific seven-week period which began when they were beaten in the League Cup Final by Birmingham City.
Subsequently knocked out of the Champions League by Barcelona and the FA Cup by United, their league form has been poor with five draws and a single win over Blackpool in six games before defeat at Bolton finally ensured that their wait for a trophy would extend to a seventh year.
United have won six of their past seven meetings with Arsenal in all competitions, including their last two at Emirates Stadium.
Chelsea have not entirely given up hope of retaining their title but clearly need to beat Spurs and hope Arsenal do them a favour to keep their Old Trafford showdown meaningful.
Spurs look to have lost out to Manchester City in the battle for fourth place as they now trail them four points.
City host bottom club West Ham United on Sunday and, with a game in hand on Arsenal, who they trail by five points, are eyeing a third-place finish and its direct path into the Champions League group stage.
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