United's smash and grab win at Anfield changed the landscape for a team- and their embattled manager- seemingly stuck on a downward spiral.
Indeed, Van Gaal appears to have that fortunate general knack of gaining an unexpected victory just when it looks as though the battle has turned against him: that the chips are down.
Maybe though, that is part of the argument to keep him at United until the summer.
Despite being under pressure all season, Van Gaal has a 100% record with United against our oldest and most hated rivals, and this latest victory lifted some of the gloom that has rapidly enveloped the boss and his players.
Afterwards, the Dutchman claimed that his side were back in the title race.
That felt like a stretch: a big stretch, but it was a result that changed the landscape both for United and the manager, whose future would have been as bleak as the January weather with defeat.
United moved to within two points of the top four with the victory and it injected a vital shot of belief, impetus and confidence into a side that has played without these three precious commodities for much of the season.
Yet it could also be argued that this match was further evidence that Van Gaal has taken United backwards.
This was a performance largely in keeping with many of United's others this season: turgid, uninspiring and the polar opposite from the high-tempo, high-pressing style that provided last season's thrilling victory in the same fixture.
We played the hosts off the park for most of that 2-1 win at Anfield last March, whereas here,
whilst they didn't outplay us to quite the same extent, a Liverpool team arguably weaker than the side of last season had the better of much of the match.
The result was typical of the Sir Alex era, the performance anything but- United's win did not match some of the flamboyance and flair of Anfield games past, but the nature of it will surely provide Van Gaal's vintage with a vital boost with four months of the season remaining.
So where does this leave us.
Hopefully, yesterday's victory with have a galvanising impact on the team in the second half of the season, but it's vital now that we kick on from this with momentum-building victories against Southampton and Stoke with the trip to Chelsea fast approaching on the horizon.
We must make sure that the Liverpool win is not another false dawn or the pressure that has, temporarily at least, eased on Van Gaal will return with abundance.