That moment came in the 73rd minute when Jay Rodriguez finished off a wayward header by United's Nemanja Matic on the corner.
Their squad is crammed full of wonderfully potent performers such as Juan Mata, Paul Pogba, Romelu Lukaku and Alexis Sanchez, yet the Premier League table, which shows them 16 points behind City, does not lie.
Here's how the footballing world reacted to City's title win.
Manchester United fans were delighted to see their record signing back to his best as he prodded past Ederson twice to level the derby and help delay City's title charge. Everyone was one more touch, one more trick, one more flick, one more turn'.
"I think it's a unsafe week for us, because we come from a very good result, and also I think a few consecutive victories in the Premier League, so our moment is good, playing against a team that is still fighting, and they will fight until mathematically it's not possible".More news: Driving Ban and Large Fine for Ant McPartlin
City had won convincingly against Tottenham Hotspurs on Saturday, leaving their fate in the hands of United team waiting to engage the Baggies the next day. "The amount of goals, chances and points, to do that in the Premier League, with the contenders we have, is because the players are so good". If Jose Mourinho-coached Man United can win all of their remaining matches, they can reach maximum 86 points in total.
"We still need to improve to reach the last level which is the most hard thing".
Mata knows how significant it could be if this year's team win the trophy in the coming weeks, even if Spurs represent hard opponents at Wembley.
Apart from stand-out displays at Arsenal and City Pogba has struggled to justify his mega-price tag this season and was stunned when Mourinho chose 21-year-old Acadamy product Scott McTominay ahead of him in some games. Of their five remaining matches, no team is now higher than 13th in the table.
"As soon as the game started, something was weird - the atmosphere of the stadium, the team - it's so weird from what we saw from that team a week ago", he told Sky Sports.