A week after preventing its neighbours from clinching the title in front of their own fans by rallying from 2-0 down to win 3-2, United delivered a similarly unlikely result as managerless West Brom pulled off one of the shocks of the season.
"Manchester City, we've won them the league", the Baggies fans sung from the away end as their team closed in on victory.
Jose Mourinho said: "It was a bad reaction after the City victory, the effect of that is complicated football". They are the 10th team in top-flight history to achieve this. It was a slow game and we didn't play well at all.
"They always had time to organise themselves". "And then to get second in the league which is not the ideal position, but it's the position we want to finish now".
"Our Time. Our City".
In situations such as these - with United being second in the table - Ferguson may have trusted his players to play with more freedom and blow West Brom away, which begs the question of whether Mourinho has the same faith in his squad to deliver. "So happy to be able to share another trophy with our unbelievable fans!" tweeted City's captain Vincent Kompany.
City subsequently join the United team of 2000/01 in becoming the only Premier League club to win the title with five matches remaining. City's other two Premier League triumphs, in 2012 and '14, were sealed on the final day.
"I had a feeling when I woke up this morning", Kompany said.
City's 3-1 win at Wembley against Tottenham on Saturday meant Manchester United had to avoid defeat at home to West Brom to keep their slim hopes alive.
Nobody expected this result, so it was a nice surprise for City to become champions one week earlier than they had anticipated, and for that they owe thanks to West Brom, who made sure they knew that.
There are five matchdays left for the 2017-18 Premier League season to be over, and City have dominated the title race, scoring a total of 93 goals and losing only twice so far.
United, meanwhile, will attempt to hold onto second place and automatic qualification into the Champions League group stages next season.