Pep Guardiola's body language does not exactly disguise his feelings and it screamed out just how much Manchester City's victory at Chelsea meant to the Premier League champions and their manager.
The 1-0 win, thoroughly deserved and confirmed by Gabriel Jesus's deflected 53rd-minute strike, wrote Guardiola's name even more indelibly in Manchester City's history as this was 221st victory in all competitions, the highest ever achieved at the club.
This, however, was a side issue after a performance that carried all the hallmarks of champions and sent out a powerful message to Chelsea and any other rivals that Manchester City will not give up their crown easily.
Not that you would necessarily have known if you had indulged in a spot of Guardiola watching in his technical area, a blizzard of discontent one moment, agitation the next, delight when Gabriel Jesus struck and the tic-tac micro-management that is his trademark.
When a Kevin de Bruyne pass failed to find its target late on, the thwack of a plastic bottle could be heard around Stamford Bridge as it hit the turf before ricocheting into the air.
When another passage of possession went astray, Guardiola spun on his heels and ordered substitutes Raheem Sterling and Fernandinho into a quick change to get them on before Chelsea had the chance to snatch an equaliser that would have been grand larceny.
In the end, all was well and it was a more relaxed Guardiola who was able to reflect on a display that was hugely impressive from first to last, the only negative being City's failure to convert the host of second half opportunities that could have made the manager's last few minutes far more relaxing.
Guardiola has faced questions this season about his lack of a recognised striker, especially when they barely mustered a shot amid the struggles of goalless draw at home to Southampton.
He argues his squad has the quality and adaptability, as well as the trophies, to cope and this was demonstration of what Guardiola means, with Phil Foden starting as a false nine but Chelsea also being confronted by an array of attacking threats.
Guardiola said: "Sometimes we believe we need a proper striker to finish but the important thing is the way we play. The most important thing is doing it as a team and as a unit. It's like last season. Sergio Aguero was injured all year and we won the Premier League."
He added: "We played for each other, ran for each other and passed the ball for each other. I'm watching The Ryder Cup and I'm seeing how they play for each other. That is nice when you play football too. It's just three points of course, but the way we played was so good.
"It's a good way to start this fascinating week we have ahead of us."
Fascinating indeed, as Guardiola and Manchester City travel to Paris St-Germain in the Champions League before meeting Liverpool at Anfield next Sunday.
This was the perfect start and it came in a game in which many ranked the champions as underdogs given Chelsea's superb start to the season, their status as Champions League holders, and the addition of £97.5m striker Romelu Lukaku.
Guardiola was heavily criticised for not selecting a holding midfielder in that Champions League Final loss. He did not make the same mistake here as Rodri was the man for the job, knitting it all together as City controlled the important phases of the game.
Lukaku had one of those afternoons when his touch was poor and his radar was off but in his defence he was starved of service and City's defensive partnership of Aymeric Laporte and Ruben Dias presented a very formidable barrier.
It was a sign of how at ease City were, and also how Chelsea were betrayed by their own negative outlook, that Thomas Tuchel's side did not have a single shot on target, a stark statistic at Stamford Bridge.
Bernardo Silva, who also had questions posed about his future when City were pursuing Tottenham's Harry Kane, has looked a player re-invigorated and was again at the heart of so much of City's best work.
Jack Grealish carries his £100m price tag like a pleasure not a burden, probing throughout, smiling his way through some hefty challenges and looking perfectly at home with the champions.
This was a win that was significant in the wider context, however, because defeat for City would not just have been a body blow at the start of these vital eight days but would have given Chelsea the belief that they might just be untouchable this season.
Instead, City did not give Chelsea a sniff, took charge from the kick-off to play with the composure and intent of champions and will have left west London in good heart after giving their Champions League Final conquerors a lesson.
Chelsea, in contrast, were strangely passive. Whether it was Tuchel's selection of three defensive-minded midfielders in N'Golo Kante, Jorginho and Mateo Kovacic or a lack of conviction, this was a shadow of the team that has looked such a force under Tuchel.
Manchester City looked and played like a team in the mood to lay down a marker, to show their rivals they mean business and Chelsea ran straight into it.
Guardiola will not get carried away by one result and nor will Tuchel - quite correctly - but City kicked on to another level after winning at Chelsea last season. They will hope this win has the same effect.