Arsenal controlled the match from start to finish, as a Gabriel Magalhães tap in gave them a narrow 1-0 win over their London rivals Chelsea.
It was an impressive performance from the Gunners, who moved back to the top of the table with the win. The North London side now have 34 points from thirteen matches, which is making their title contenders remarks even stronger.
Chelsea struggled to get out of first gear at Stamford Bridge. They lacked product in the final third, and were defensively weak at times. It's a second straight league defeat for the Blues, which leaves plenty of work for Graham Potter to improve on.
Honeymoon Period over?
When Graham Potter replaced Thomas Tuchel as manager, he started with style and quality. He led Chelsea to a nine game unbeaten streak, including strong wins against AC Milan and Wolves.
Tactically, the West London side looked more assured in possession and defensively solid. But, that now seems like a distant memory for the Englishman.
The loss to Arsenal made it back to back Premier League defeats in a competition they are now winless in four. For a team that has expectations to qualify for the Champions League, it is not good enough from Chelsea.
The praise Chelsea were given in Potter's opening weeks, turned to criticism against Arsenal. In defence, they were consistently opened up by the likes of Gabriel Jesus, with Marc Cucurella being a particular weak point at left wing-back.
However, the more worrying aspect for Potter will be the lack of goal threat from his side. The Blues had just one shot on target, and created only 0.26xG. It's worrying numbers for a team so used to success.
New signing woes
In the summer, Chelsea made six first team signings. The likes of Raheem Sterling and Pierre-Emerick Aubameyang were high profile names, but was it was they needed?
The dismal result to the Gunners continues a worrying season for Chelsea's latest blues. Aubameyang and Sterling offered little in attack, as they contributed to their low xG of 0.26. Cucurella was the weakest link on the pitch for Potter by being repeatedly out of position for the hosts.
Although Wesley Fofana and Kalidou Koulibaly did not feature in the London derby, neither have had standout starts to their Chelsea careers. The summer transfer window seemed chaotic from the two-time European champions. Todd Boehly was leading his first opportunity to invest in the club, but it seems he may have got it wrong.
Saliba continues to impress
Arsenal have been sensational this season. From back to front, they've looked composed on the ball allowing them to create clear cut chances consistently. To be able to play a high line and keep possession, it requires huge trust in the centre-backs.
William Saliba provided that trust once again against Chelsea, just like he has all season. The Frenchman made three clearances, one block and two tackles in a standout performance in defence.
In one particular moment, he timed the offside trap perfectly, allowing the visitors to regain possession quickly. His partner, Gabriel, was just as assured with the ball, and even provided the crucial goal in the 63rd minute.
Arsenal have struggled defensively for several years under Unai Emery and Mikel Arteta, but it seems they may now have the centre-back to push them to the next level.
Jesus can do everything but score
When Gabriel Jesus joined Arsenal from Manchester City in the summer, expectations were high. The Gunners had lacked a consistent talisman ever since Aubameyang's decline. The hope was that Jesus would be able to replicate that impact.
However, the Brazilian seems to be able to do everything but score. The match against Chelsea means the forward has now not scored for nine matches in a row, with his last goal coming against Tottenham Hotspur in the North London derby. For most fans, it would be concerning to see their striker scoring so little, but the Brazilian's build-up and work rate is just as important.
The 25-year-old links up Arsenal's front line perfectly, and brings Gabriel Martinelli and Bukayo Saka into the match more often. This created a fluid attack against Chelsea, that caused major problems for the hosts. Cucurella especially struggled due to Jesus' dynamic movement.
The goals are not flowing for Jesus at the moment, but no one can criticise his build up play and overall movement. Any success which the Gunners earn this season will be heavily dependent on the striker.