Manchester City's derby day win at Old Trafford was a triumph for everyone at the club - but Pep Guardiola's smile was wider than most on Sunday evening.
The Spaniard provided a tactical masterclass as City won 2-1 at the home of their fiercest rivals.
While the scoreline was close, in truth City dominated for the vast majority of proceedings at the Theatre of Dreams and were fully worth their 14th successive Premier League victory.
Our man David McDonnell was at Old Trafford, and here are five things Pep got right during the game...
1. Brought Gundogan on and moved Fernandinho to defence
Vincent Kompany felt something and was unable to play the second-half.
Instead of bringing on a like for like in Eliaquim Mangala, Guardiola switched Fernandinho to central defence and brought on Ilkay Gundogan in his place in midfield, ensuring City kept possession and the ball moving forward in a key area.
2. Not playing with a recognised striker
Even though Gabriel Jesus got the nod ahead of Sergio Aguero, he didn't operate as an orthodox striker. Jesus was drifted out wide on the left, with Leroy Sane switching to the right and Raheem Sterling operating as a false nine.
The upshot was it gave United's defence no-one tangible to mark and allowed City to constantly tease and probe them.
3. Sticking to his famed passing philosophy
The game was less than 10 minutes old when Guardiola berated skipper Kompany for hoofing an aimless ball forward, a speculative punt which came to nothing, the City boss gesturing manically from the touchline to keep the ball on the ground, something the Blues did throughout, passing their way through United with ease and cutting through them time and again.
4. Giving Jesus the nod over Aguero
Sergio Aguero has not been at his sharpest in recent weeks, but has an impressive record when it comes to Manchester derbies, scoring eight goals in 11 games against United.
But Guardiola recognised Jesus would cause United more problems with his pace and clever movement, dovetailing well with Sane and Sterling, while Aguero didn't make it off the bench.
5. Bringing on Mangala to tighten things up
Guardiola could never be accused of parking the bus like Mourinho, but he recognised when he needed to tighten things up and, with City leading 2-1, he brought on Mangala for Jesus just before the hour mark to do just that.
Bringing on Mangala, who made some key blocks in the final half-hour, gave City extra security and enabled them to see out the win.