Arsenal looked a cut above Chelsea as they ran riot in Orlando against their London rivals.
The Gunners - for whom Oleksandr Zinchenko was making a debut - looked fitter, stronger and faster than Thomas Tuchel's side, with Gabriel Jesus pouncing on a defensive error to open the scoring with a fine chip over Edouard Mendy.
Martin Odegaard doubled the lead with a controlled finish in the first half, and although Chelsea were distinctly second best, Mason Mount struck the post with a fierce effort just before half-time after being found by Raheem Sterling.
Bukayo Saka fired home from close range in the second period after Mendy had pushed out a Granit Xhaka effort, with Albert Sambi Lokonga heading a fourth from a Cedric cross.
Here are the night's winners and losers.
Winners
Gabriel Jesus
He's just going to score goals, isn't he?
The Brazilian looks to be exactly the player that Mikel Arteta and Arsenal needed, one that is gifted enough to be bracketed just under the very best, but also young and hungry enough to believe that he has got something to prove.
It is after all no shame to not get into the Manchester City side that we've all seen over the past few years, but Jesus won't think of it like that.
At Arsenal he has a stage upon which to shine, and one that that will probably get him a lot more acclaim than his not inconsiderable efforts for City did over the years.
His expert chipped finish for the opening goal here showed exactly what he can do, and will probably keep doing this season.
Martin Odegaard
The Norwegian wants to be the Gunners captain on a full-time basis, and this was a good way to show exactly why he should be.
Now having evolved from his days as the teenage Real Madrid wonderkid, you sense this could be the time for Odegaard to kick on in his career and take a step towards the very best around. To do that he will need to add more goals, and he got one here.
He deserved it too, with his movement and clever passing a key element of a Gunners side who looked crisp, and several levels ahead of Chelsea in terms of form and fitness.
Oleksandr Zinchenko
A seamless start for the Gunners new boy, who only played 45 minutes but looked very much at home at left-back.
The Ukrainian was constantly getting forward to support the Arsenal attack, which would often come down the left with Ben White stationed at right-back and keeping things tight against Timo Werner.
Zinchenko dovetailed well with Gabriel Martinelli ahead of him and Granit Xhaka to his right, and this could be the start of something beautiful.
Losers
Trevoh Chalobah
With Kalidou Koulibaly signed and Jules Kounde continually linked, this really isn't the time for Chelsea's impressive young defender to struggle.
But one look at Tuchel's face after his error let Jesus in for Arsenal's opener said everything.
Chalobah has come a long way in a short space of time, and young players are allowed to make mistakes - indeed, this is a pretty good choice for a time to make them - but the mistake coupled with the injury which forced him off before half-time made for a forgettable evening for him.
He might face a struggle to hold down a place this season.
Conor Gallagher
It hasn't been a good week for the England midfielder, who followed up *that* penalty against Charlotte by being hauled off at half-time here.
Again, this is pre-season, but it was billed as a big one for Gallagher following his return from stellar loan spell at Crystal Palace and the vow that he could force his way into Tuchel's plans.
A rather agricultural lunge on Saka in the opening stages of the game wouldn't have impressed the German and would have probably have been harshly punished in the Premier League, where he'll face a fight for minutes.
Thomas Tuchel
The German cut an agitated figure on the sidelines in Orlando, and this was not a good look for Tuchel or his Blues side just two weeks out from the Premier League opener at Everton.
At the first drinks break in the first half Tuchel could be seen loudly shouting at his Chelsea players and demanding more effort, but they just didn't look up to speed with the Gunners as they were ran all over in the first half.
Tuchel won't be panicking, but he has much to ponder.
