Emery's Arsenal next face a London derby at Chelsea on Saturday. Our team, with more time, will play with this personality. Eliaquim Mangala and Danilo are injured while World Cup starters Kevin De Bruyne and Raheem Sterling are expected to play after a late return to the side.
David Silva could be a question mark for Sunday's fixture as well.
The visitors' level of performance, given how few weeks there have been since the World Cup and how little time they have had to prepare for the season, was incredible.
"In general to be at this moment of the season, with the desire to run and run, it was the same last season". The wide man cut inside from the left wing and drilled the ball beyond the routed Czech goalkeeper on 14 minutes. He did just that in the first half with this opening goal, which proved to be the victor.
Cech bailed out his ailing team-mates by thwarting Aymeric Laporte at point-blank range having parried Riyad Mahrez's free-kick.
Emery opted to start Cech in goal despite bringing in Bernd Leno in the summer and stood by his decision afterward.
The Gunners were far too structured and predictable, nearly robotic as they consistently played short passes out from the back at every opportunity. You would have put your mortgage on the Argentine scoring, but Cech spread himself well to repel the ball out.
The England forward was outstanding despite having been back in training for less than a week after his exertions in Russian Federation and scored the opening goal as Arsenal, under new management, were swept aside at the Emirates. Perhaps we'll see more from him when Lucas Torreira is installed as his regular partner.
However, Arsenal fans quickly hit back with a very good response, singing: "He's won more than you, he's won more than you, Arsene Wenger, he's won more than you!"
One difference for City this season is the presence of Benjamin Mendy at left-back.
Another worry for Arsenal is that their left-back situation worsened when Ainsley Maitland-Niles hobbled off in the first half with a leg injury. Not every game will be against a team as good, as well coached, as cold-blooded as Man City.
And the best thing for Guardiola is, this wasn't even the Champions at their best.
Installed as heavy favourites to finish top again - which would make them the first team to defend the title since Manchester United in 2008-09 - City's ruthless performance was ominous for their rivals.