Pep Guardiola delivered the first meaningful blow in a rivalry with Jose Mourinho that will become a central part of the Premier League's narrative as Manchester City recorded a well-merited win against Manchester United at Old Trafford.
The pair's history of animosity with Barcelona and Real Madrid in Spain's La Liga meant their first Premier League meeting since assuming control on either side of Manchester provided a colourful backdrop to the build-up to this derby.
And when the action got under way on the field, it was City who put a marker down and put Manchester United in their place with a peerless first 40 minutes followed by resilience to maintain their 100% start to the season.
Guardiola wins battle with Mourinho
This was always going to be much more than the Manchester derby - this was as much about Mourinho against Guardiola on the Premier League stage, fighting for supremacy in Manchester.
And this was Spaniard Guardiola's day on every level as City claimed the win and his celebrated methods were on show for all to see at Old Trafford, the fiercest enemy territory.
Mourinho was a chastened figure post-match, reduced to blaming referee Mark Clattenburg for not awarding two second half penalties for what he felt was City keeper Claudio Bravo's foul on Wayne Rooney and Nicolas Otamendi's handball.
It was an act of straw-clutching, although the Portuguese fully accepted City's first-half superiority when he admitted he and his players got it wrong.
The bottom line is United were second best and this was something of a cold shower for the over-excitement of some who believed 'The Special One' could apply an instant fix to the faults of the past three seasons under David Moyes and Louis van Gaal.
Mourinho's decision to play Henrikh Mkhitaryan on the right in his first start since his £25m summer move from Borussia Dortmund was a dismal failure - and he admitted some of his players struggled to cope with "the dimension of the game".
The Armenia captain was removed at half-time in a reshuffle that also saw Jesse Lingard taken off, Marcus Rashford and Ander Herrera sent on, and the completely anonymous £89m midfield man Paul Pogba and Marouane Fellaini pushed forward, with Wayne Rooney shunted out to the right.
In other words - Mourinho's selection went wrong.
He said: "I had two or three players in the first half that, if I know what is going to happen, I don't play them. This is football, though, and sometimes players disappoint managers.
"It's my fault because I'm the manager and it's always my fault because it's my choice."
Guardiola was bold enough to play Kelechi Iheanacho as replacement for the suspended Sergio Aguero and the 19-year-old responded with his ninth goal from just 13 shots on target in the Premier League.
And his introduction of Fernando for the youngster after 53 minutes demonstrated a pragmatism that is often overlooked amid Guardiola's purist instincts. He was prepared to use a shield when required.
City were also prepared to work for their success, running a total of 119.63km in comparison to United's 111.34km. Guardiola demands the full package from his players.
It was not all perfect as his selection of the uncertain Claudio Bravo in goal ran a fine line with failure - but all's well that ends well.
The embraces with long-time foe Mourinho at the start and finish were cordial enough - and if Guardiola did get around to having that glass of wine in the Old Trafford manager's office when his media duties were completed it would have tasted sweet.
Man City make their statement
Manchester City made their intentions clear when they lured the most coveted man in management to Etihad Stadium - and Guardiola's team have wasted no time in making big statements of their own.
The Catalan has opened up with four straight Premier League wins, this victory at Old Trafford marking them out as the team to beat in the title race this season.
It is, of course, early days but City's ability to win with key players either suspended, injured or working their way to full fitness means a significant marker was put down in this derby win.
It was a win achieved without the banned Aguero and without influential captain Vincent Kompany who is nearing a return, as is summer signing Ilkay Gundogan, who was also absent.
Leroy Sane, the £37m summer signing from Schalke, made a lively appearance as a substitute here and will be a formidable force when fully fit.
John Stones was outstanding when United's second-half siege came, demonstrating why Guardiola was satisfied to spend £47.5m on the young England defender to bring him from Everton.
Kevin de Bruyne was also a key figure, scoring one goal and being involved in the other. He has been directly involved in 32 goals in 46 appearances for Manchester City, scoring 17 and assisting in 15.
And when Guardiola studies the statistics, an 81.8% passing success rate will please even this perfectionist, who expressed his satisfaction with this two-dimensional City display - glorious, clinical football in the first half and solid resilience in the second.
City restricted United to their fourth lowest home possession share in the Premier League since the 2003-04 season, just 39.9%
Manchester City's squad looked short of inspiration and motivation in the understated presence of Manuel Pellegrini last season - this problem looks to have been cured already by Guardiola.
It has been an impressive start. Those with Premier League title aspirations now know what they have to beat.
Is Bravo the answer?
Pep Guardiola has invested a lot of faith in Claudio Bravo after showing England goalkeeper Joe Hart the door and paying £17m to bring the 33-year-old Chile international from Barcelona.
It was, therefore, no surprise to hear Guardiola mounting a passionate defence of his man despite a performance that left City and their supporters living on their nerves.
In Bravo's defence, he has barely had any training sessions with his new team-mates and a debut at Old Trafford is always a daunting introduction.
Guardiola's backing for his keeper, while understandable, was at odds with a display that occasionally threatened to spread panic in City's ranks.
He was hesitant and occasionally too slow to clear with the ball at his feet and once he came from his line to claim a first-half free-kick, Bravo had to catch it. He did not, allowing Zlatan Ibrahimovic to score and give United hope.
Guardiola praised Bravo's willingness to take responsibility and is happy for his keeper to take a high-risk approach in exchange for the rewards he believes it brings.
It is too early to say whether Bravo will be an upgrade on the banished Hart but those who believe England's first-choice keeper has been sent into exile too soon will not have had their worries eased by this performance.
They will have to trust Guardiola's judgement - and he has not got anything wrong so far.
When will Rashford start?
While Mourinho bemoaned those players who struggled to cope with the unique demands of the Manchester derby, he had no such complaints about Marcus Rashford.
Mourinho said the 18-year-old looked like he was "playing against Salford City under-18s" in a second half performance that combined pace and a fearless approach - and almost an equaliser only for an offside Zlatan Ibrahimovic to get a touch on his goal-bound shot.
The question will continue and the clamour will grow for Rashford to start in an area of Mourinho's squad that is starting to look over-crowded.
Rashford was the player who put City on the back foot with his speed. It will be one of Mourinho's most urgent tasks to integrate this brilliant young talent into his team.
It then begs further questions, with Ibrahimovic seemingly untouchable as the main man, about where Rooney fits in and how Mourinho can shuffle his resources to maximise the potential of Rashford, Antony Martial, Mkhitaryan and Juan Mata.
Ibrahimovic had all of United's three shots on target as well as four of their six off target, so it is likely to a case of who plays with the 34-year-old Swede.
Rashford, on this showing, cannot be denied his starting place for much longer.