The opening stages of the game saw both sides advancing from midfield on the wings to reach the final third. Chelsea’s primary means of creating was to find Hudson-Odoi, but he was covered well by Martinelli tracking deep to block crosses or force bad crossing positions. Hudson-Odoi did cause problems when he was found in space against Saka 1-v-1 or he was able to cut inside. Chelsea won a number of corners from these situations, but only created one opportunity from them.
Arsenal’s possession would see them also advancing on the right regularly, where Özil would move out wide to support Pépé and provide an option for forward passes (Lacazette and Martinelli attacking the left wing together less frequently). Özil, moving wide, found spaces to receive the ball, while Pépé caused a lot of problems for Emerson and Chelsea’s defenders when dribbling with the ball — going past players, holding on to the ball, and drawing fouls. Emerson receiving a yellow card early on would ensure the constant threat of Pépé’s dribbling throughout the match, as well as having consequences later on in the second half — i.e. not fouling Martinelli during the counter for Arsenal’s first goal.
Mustafi’s mistake was a turning point in the first half, which allowed Abraham to go through 1-v-1 on goal, win a penalty and see David Luiz sent off.
After conceding the penalty, Arsenal made adjustments utilizing the players already on the pitch, without making any changes from the bench. Arsenal thus found themselves in a situation that had Bellerin, Mustafi, Xhaka, Saka forming a back-four and Özil and Torreira playing as central midfielders, down to 10 men, away, and losing 1-0 after 26 minutes.
Chelsea would go on to dominate possession following the red card, but again failing to create many problems against Arsenal’s deep defending. During the final minutes of the half, Arsenal would actually go on gain possession — Chelsea had a difficult time pressing them and maintaining organisation when defending deep. Lacazette now moved over to the left to join Pépé and combine (Bellerin joining more often to use his speed), and Arsenal would get behind Chelsea’s backline a few times before the end of the half.
Chelsea made an aggressive and fast start to the second half which caused Arsenal a lot of problems to control though their deep defending, but after this initial period the game went back to a slow possession game for Chelsea.
Arsenal made the first change to bring Guendouzi on for Ozil to increase their defensive characteristics ahead of their backline, before Martinelli’s speed to recover the loose ball from Arsenal’s defensive corner and carry it forward to score would draw the game level—Emerson on a yellow card and choosing not to foul.
Chelsea’s changes came shortly after, with Barkley replacing Kovačić and Mount replacing Kanté. Theses changes gave more attacking characteristics in midfield, but not were incongruent with the final change to switch to two strikers. Keeping Kanté on in a deeper (double-pivot) role would’ve made more sense to me, having him cover the wide areas against Arsenal’s wingers during counters, especially with Emerson on a yellow card against Pépé. Assuming Chelsea would go on to take the lead (potentially with two strikers on the pitch) Kanté’s defensive qualities would’ve been useful to help hold the lead. Furthermore, Arsenal were taking advantage of loose balls and second balls in the final third (long play from the back), having a much easier time in recovering those without having to deal with Kanté.
Chelsea’s final change was to bring on Batshuayi for Willian (4-4-2, Mount on the left), followed by Jorginho creating a chance for Barkley with a pass into the box. Arsenal would finally bring on Holding for Pépé following this and change to play 5-2-2 (wing-backs and central midfielders moving up to join Arsenal attacks) with Martinelli and Lacazette as the front two. Chelsea would go on to score through a corner, but would then have to defend the final moments of the match with Abraham injured, where Arsenal attacked with numbers and managed to find an equaliser through Bellerin moving inside onto his left foot.
Chelsea missed a couple of opportunities, but failed to create too many chances to score while being an extra player up for the majority of the game. Down to ten men and a goal behind after 26 minutes, Arsenal went on to win the remainder of the game 2-1.