MANCHESTER City were crowned Premier League champions on Sunday after Manchester United crashed to a shock 1-0 defeat against West Brom as coach Pep Guardiola added a first English title to his three apiece at Barcelona and Bayern Munich.
City had moved within touching distance of the title with a 3-1 win at Tottenham on Saturday.
They clinched the silverware 24 hours later thanks to West Brom forward Jay Rodriguez's 73rd minute header at Old Trafford although Guardiola may have missed the crucial moment after opting for a round of golf with his son instead.
City captain Vincent Kompany led the celebrations, tweeting: "Champions! What a great feeling! So happy to be able to share another trophy with our amazing fans!"
City captain Kompany watched the match at the house of his Mancunian wife Carla Higgs, who invited her United-supporting father to join the party.
The gathering was captured in a social media post and Carla's father is seen wearing a United shirt as Kompany celebrates.
"It shows how football is lived in Manchester as we have Reds in the family and Blues but today was a day for the Blues. It is banter. It's been a great day," Kompany said.
Kompany was caught on camera speaking with his City team-mates Kevin De Bruyne and Kyle Walker on Face-time to celebrate the success, with Carla's grand-mother heard asking him "Do they want to come round?"
He added: "You can't take (winning the league) for granted, I've won three now but there's so many we've missed.
"My team-mates will roll their eyes as I want to see the reaction from us next season as I've never been able to retain a title."
Kompany was quick to pay tribute to Guardiola for getting the best out of his players in his second season.
"I have learnt from him. When I was 20 I would have been a perfect player for him," he said.
"Everyone that plays under him will have had success because of him, because he has the ability to unlock the full potential."
United had denied City the chance to wrap up the title last weekend when they came from two goals down to beat their bitter rivals 3-2 at the Etihad Stadium.
But Jose Mourinho's men still ended up handing the trophy to City with a lacklustre display against bottom of the table Albion, who had won only three times in the league this season before this weekend.
"Manchester City, we won it for you" chanted West Brom fans at full-time as United supporters began jeering in frustration at their side giftwrapping the title for City.
City manager Pep Guardiola might have rubbed his eyes in disbelief at events at Old Trafford when he returned from his round of golf with his son. His decision to forego the match looked justified considering West Brom's dreadful form, but the visitors easily coped with United's ponderous attacks and looked dangerous going forward.
West Brom is still nine points from safety and looks destined for relegation. United is now just one point above third-place Liverpool.
United should have had a first-half penalty after Craig Dawson caught Ander Herrera, but complacency seeped in and West Brom showed fight under caretaker boss Darren Moore that has been sorely lacking this season.
United was too narrow and predictable, with wide players Alexis Sanchez and Juan Mata constantly cutting inside and leaving the midfield congested. By the hour mark, Mourinho had brought on attacking players Jesse Lingard and Anthony Martial for central midfielders Ander Herrera and Paul Pogba but things didn't really improve.
It wasn't the best day for Romelu Lukaku against his former club, either. When his first touch wasn't heavy, he found Ben Foster an impenetrable barrier as the West Brom goalkeeper produced impressive saves from Lukaku in each half. Ultimately, Rodriguez was the savior for West Brom - and the title-clincher for City.
Just days after the Football Association announced that a charge of racially abusing Brighton's Gaetan Bong had been found "not proven," the forward pounced to score from close range after United midfielder Nemanja Matic headed the ball back into his own area at a corner.
Mourinho said his players were "masters in complicated football." "We couldn't play fast, we couldn't think fast, everything was complicated," he said. "One more touch to control the ball, one more flick, one more trick. We always gave them the opportunity to be solid, compact in the low block with strong physical players.
"They always had time to organise themselves. We wanted to dribble and dribble, and everything was complicated."
Guardiola is the first Spanish manager to win the English title.
He and Mourinho are old rivals from their time in Spain when the United boss managed Real Madrid.
Mourinho was hardly effusive in his praise when asked about City's success, but did concede they deserved to be champions.
"I have won titles. City were the best team, sooner or later they would get the points, so no dramas when the best team wins the league," Mourinho said.
"I saw lots of people in the moon because we won against City. You could see the difference in the attitude to players compared to last week. We deserve to be punished."
City are 16 points clear of second placed United, who can only take a maximum of 15 points from their remaining five games.
Winning the title with five matches to go makes City the joint earliest champions in the Premier League era - matching the achievement of the 2000-01 Manchester United team.
"We did it! An amazing journey to get here. All the lads have done so well and it feels great to be part of this really special group of players," City defender Kyle Walker said.
Sergio Aguero, who became City's record goalscorer this season, added: "Ecstatic about clinching another title with this great team, and with all the support of our fans. Let's celebrate!"
City midfielder Kevin De Bruyne, a candidate for Player of the Year, said: "Unbelievable season for us. Very happy to call us champions this year!" It is the fifth time City have been English champions and the third time in the last seven seasons.
City defender Benjamin Mendy, who missed most of the season due to injury, turned social media blue as he tweeted: "We are f*****g champions congratulations boys!"
Guardiola had planned a day of golf with his son Marius on Sunday, so the Spaniard might have learned of his first Premier League while on the course.
Speaking after the win over Tottenham, Guardiola admitted winning the title in England would be one of the greatest achievements of his glittering career.
He won three league titles with Barcelona and twice lifted the Champions League trophy during his Camp Nou reign.
The 47-year-old also took the German title three times with Bayern Munich, but he believes the unique strength in depth and physical demands of the Premier League makes this triumph among his very best.
He also conceded it was sweet to triumph in a country where some critics claimed his purist principles couldn't flourish.
Guardiola and his players will have the chance to celebrate properly on Sunday when they host Swansea in their next fixture.
It was always a matter of when rather than if City would be champions after they led the way for most of the season.
Only in the last 10 days, as they lost to United and were knocked out of the Champions League quarter-finals by Liverpool, had City's quality been called into question.
They gave a superb response with a swaggering win at fourth placed Tottenham. Now, driven on by stars De Bruyne, Raheem Sterling and David Silva, Guardiola's men can focus on establishing themselves among the Premier League's all-time great teams.
Some pundits are already ranking City - who at one stage this season won a record 18 successive league games - while it may be premature to place City in that rarefied air, they could make a case by breaking the Premier League points record of 95 set by Chelsea in 2004-05.