United were top of the league at the end of November but did it signal the beginning of the end for the Dutchman?
When Bastian Schweinsteiger bundled the ball into the net in stoppage time at Watford on 21 November, United - briefly - rose to the Premier League summit.
Louis van Gaal greeted the German midfielder with a big grin and a hug as he walked off the pitch at Vicarage Road.
The boss had achieved victory - a third in a row- without a recognised striker while Troy Deeney's penalty was the first we had conceded for nearly 11 hours.
The same day, Arsenal lost at West Brom and City were comprehensively thumped by Liverpool at the Etihad.
Well placed in the league and going well in Europe, there was a sense among the fans that United might achieve something this season and not just finish in the top four which had passed as adequate the previous season.
Victory over PSV Eindhoven at Old Trafford would book United's place in the knockout stages of the Champions League and the same result at Leicester would cement the status as title challengers.
Instead, it's a week that could well end up being remembered for the moment the wheels began to come off.
It is a tale of missed opportunities as much as anything- we should have beaten PSV and West Ham at home and Leicester at the King Power.
We started well in Wolfsburg and against Norwich but capitulated when their first goal went in.
Then there is the manner of the dissapointments.
Five goals in six games, two 0-0 draws and one shot on target against West Ham, two against Norwich.
Six games without a win.
It isn't good.
The fall has been swift and severe.
Only two weeks ago, United were "95 per cent" happy with Van Gaal's leadership and were even contemplating an extension on his three-year contract.
His work behind the scenes- improving the facilities at Carrington and promoting youth team players- played a part.
The inference at the club was that the board were happy with results and performances despite some fans persistent misgivings about the preferred style of football.
A month is a long time in this sport, though, especially at a club when the manager is never more than a couple of bad results away from a crisis.
It would appear the outcome of this crisis will rest on two matches over Christmas, or Van Gaal and his Vicarage Road grin could be gone.