28 October 2012.
That was the last time we won a league game - in fact ANY game - at Stamford Bridge, ahead of our latest trip there on Sunday.
It was a match sealed by Javier Hernandez, a player who so often proved the scourge of the Blues, late on.
Chelsea had fought back from 2-0 down, only to have Branislav Ivanovic and Fernando Torres sent off before Chicharito's intervention.
Since then, our record in west London does not make for pleasant viewing, and reads as follows: L L L L L D L L
One win in nine - and one win in 15 in the Premier League - is an awful record that stretches back five years and makes Stamford Bridge the unhappiest of bogey hunting grounds.
It's true that we've not been helped by refereeing decisions over the years, but for whatever reason, we just always seem to struggle at Chelsea more than at any other ground.
Last season, we were thumped 4-0 on Jose's first return as United boss, before a controversial FA Cup exit at the quarter-final stage in March.
Those defeats were tempered slightly by the fact that the Blues comfortably surged to the league title and narrowly missed out on a domestic double, after a shock loss to Arsenal in the final.
To face the champions of England on their own turf is a difficult proposition for any team, but for the first time in a long while, United are possibly marginal favourites.
We come into this one second in the league and clinging to the coat-tails of City, having conceded only four goals all season.
Chelsea, by contrast, are already nine points behind Pep Guardiola's side (and four behind us), and suffered a chastening 3-0 defeat to Roma last time out.
Defeats to Burnley, City and Crystal Palace have seen manager Antonio Conte come under the first signs of pressure in his tenure at the club amid reports of a fall out with the hierarchy.
If there's ever such thing as a "good time" to play Chelsea, then this is surely it.
Chelsea's weaknesses and vulnerability have been there for all to see, so this looks our best chance since that 2012 result of finally breaking our elusive hoodoo.
But, such has been the nature of Chelsea's almost freakish stranglehold over the Reds, that a fair amount of psychological damage must have been inflicted on United during the barren run.
Man for man, we're superior to Chelsea at present so, if the players can overcome those mental demons, we've every chance of a first win on their territory for five years.
It's a battle of minds as well as the scrap for supremacy on the pitch.