West Brom drew 1-1 with Swansea in their first match after Pardew's departure, before stunning second-placed United and helping Manchester City secure the league title.
More importantly, though, it means Pep Guardiola's City team can not now be caught at the top of the table, thus handing the Catalan coach his first Premier League crown in just his second year in English football.
"We've won you the league, Manchester City, we've won you the league", sang West Brom's fans near the end of the game.
Yet they still clinch the trophy with five games to spare - a joint-Premier League record - after dominating the division for most of the campaign, and Guardiola admitted last week it would feel like "one of the best" of his career.
Pep Guardiola's men now hold an unassailable 16-point lead at the top of the table, meaning that with just five games to play nobody can catch the side which has led the league uninterruptedl since the fifth round of fixtures.
"It's a painful one for me, because a few of those guys are my friends, so it's hard for me to see them in that position", he told MUTV.
But, just a week after spoiling City's title party by beating their local rivals 3-2 at the Etihad, the way United abjectly gifted the title to their neighbours will sting.
I dont' think we deserve to lose but we gave them the opportunity to win the match by being solid in defensive and smelling a chance from set play.
The setup provided Pogba more creative freedom and showed the damage he could do with such license in the derby win. I'm a very family-orientated person anyway. City's other two Premier League triumphs, in 2012 and '14, were sealed on the final day.
The nature of their performance allowed Guardiola to hit back at those who had criticised him after the recent blip of three consecutive defeats. "They don't understand anything", he said.
The champions' dominance has been evident across an impressive 28 league victories. It's much more important what these players have done. "It's incredible. They have been unbelievable".