When the English game's two most successful clubs of the last decade met in May, United suffered a painful 1-0 defeat in front of their own fans that cost them their premier league crown.
Arsenal manager Arsene Wenger described the moment as marking "a shift in power" in the English game, a conclusion borne out this season, with his record-breaking team again leading the title race.
Saturday offers United a timely opportunity to sow some serious doubt in the Londoners' minds.
The title itself is not quite at stake yet, but Saturday's encounter could have a huge bearing on its destiny.
If United lose, they will be a yawning nine points behind Arsenal going into the frenetic festive season.
Should they win, the gap will be trimmed to a manageable three points, and Alex Ferguson's side are certainly in the mood.
Last Saturday's 2-1 win at Liverpool ended their run of five straight defeats by Gerard Houllier's side.
United have also lost their last three encounters with Arsenal. But with five wins and a draw from the last six matches, Ferguson's team appear to have found a way to live with their crippling injury list.
In May midfielder Roy Keane was United's only real inspiration on a night when Dutch striker Ruud van Nistelrooy was strangely rested and his replacement Diego Forlan proved utterly inadequate alongside Ole Gunnar Solskjaer in attack.
KEANE GROUNDED
This Saturday
The Uruguayan netted both goals against Liverpool and was on target again in Tuesday's League Cup win over Burnley -- a glut unthinkable a few weeks ago when he was marooned in a 26-game barren spell.
Ferguson has problems in midfield, with Nicky Butt definitely out. David Beckham may return following his rib injury and Juan Sebastian Veron, who has been suffering from influenza, could also play.
In defence Rio Ferdinand is close to fitness after his thigh strain and fellow centre back Frenchman Laurent Blanc could also return, although both will have a job ousting Wes Brown, who has been excellent in recent games.
Neither Van Nistelrooy, with eight goals in his last seven outings, nor Forlan are quite as hot as Arsenal hitman Thierry Henry, who has netted five outstanding goals in his last two matches.
The France striker's treble against AS Roma last Wednesday was one of the finest hat-tricks seen in the Champions League.
Saturday's deadball double against Aston Villa -- the first another swirling free kick, the second the deftest of penalties -- was evidence that, when it comes to striking a football sweetly, Henry has few peers.
However, Arsenal's current superiority over United stems from their squad strength and they have not missed the likes of David Seaman, Ray Parlour, Nwankwo Kanu and Lauren in recent weeks.
Defender Sol Campbell is suspended for Saturday's game, so Martin Keown, himself back after an injury lay-off, will partner Pascal Cygan at the heart of the defence.
