Arsenal continued their recent dominance of Chelsea as Martin Ødegaard's winning goal maintained their perfect start to the Premier League campaign.
Mikel Arteta's side are now unbeaten in their past 10 league matches against Chelsea, who struck early through Morgan Rogers but were ultimately unable to deny the champions.
Here, Telegraph Sport analyses four reasons for Arteta's 2-1 victory over his close friend Xabi Alonso.
Arsenal have played four games this season and scored identical goals in two of them. The same passing pattern, the same creator and the same goalscorer. It is an indication of how quickly Christos Tzolis has settled into life in north London that he has assisted both goals, and a measure of Martin Ødegaard's renewed confidence that he scored them both.
Tzolis registered 29 assists for Club Brugge last season and you can see how he reached such a remarkable tally. He is a winger who seems happiest when offloading the ball quickly, before the opposition defence can set themselves.
Against Manchester City in the Community Shield and against Chelsea here, Tzolis received the ball on the left flank and immediately zipped a low pass into the penalty area. On both occasions, Ødegaard charged into the area from a deeper position, took a touch to steady himself and scored from close range.
The goal against Chelsea was arguably even better than the strike against City, largely because it involved a third player: Kai Havertz. As the ball came into the penalty area, the German produced a delicious dummy to confound Chelsea defender Wesley Fofana and create the space for Odegaard to finish.
Ødegaard's winner came just a few minutes after he was left furious by a challenge from Reece James. As the two captains clashed, the Arsenal captain's face was a picture of anger. Usually so mild-mannered in his expressions, he was uncharacteristically fiery here. Perhaps that rage was flowing through him as he then sprinted away from James to score the winning goal.
Ødegaard's superiority over James, his opposite number in midfield, was one of the reasons for Arsenal's victory. The central areas were mostly dominated by the north Londoners, for whom Declan Rice and Myles Lewis-Skelly were typically combative in the key moments of the game.
The absence of the injured Moisés Caicedo was an obvious problem for Chelsea. James and Roméo Lavia had moments of quality, but they did not have the same mobility and understanding as the Arsenal midfielders, and it showed. At one point in the second half, Rice was able to drive straight through the heart of the pitch.
Havertz has started this season in excellent form, scoring three goals in four matches so far. This comes after an impressive summer in which he struck four times for Germany, two of which came at the World Cup.
Havertz loves playing against Chelsea. He loves scoring against them, too. His first-half strike was his third goal in his past five appearances against his former club.
It all makes for an enormous contrast to last season, when Havertz missed months of action because of a knee injury. The 27-year-old has always been one of Arteta's favourite players and he is moving with a real sense of purpose in these opening weeks of the campaign.
"He looks happy, he looks settled, in his personal life some great things have happened as well," said Arteta of his striker. "He feels fit, he is training every day, he has the right routine now, and he is scoring goals. Not only that, he has done amazing work for the team."
At this rate, Arsenal fans will not be seeing much of Viktor Gyökeres any time soon. The Sweden striker made his first Premier League appearance of the season as a second-half substitute, but struggled in his 12 minutes on the pitch.
Such is the depth and strength of Arsenal's squad, Arteta has two World Cup winners on his bench. Mikel Merino and Martin Zubimendi have played the same role in each of the past two games – first against Aston Villa and then here against Chelsea – by coming into the game as substitutes and helping secure the three points.
On both occasions, Arteta turned to his Spaniards when his team were protecting a one-goal lead. At the Emirates, he called for Merino directly after a passage of sloppy play in the centre of the pitch.
The intention has been for Merino and Zubimendi to add muscle, intelligence and calmness in moments of stress. It took a few minutes for them to do so here, but the former Real Sociedad pair eventually took a hold of the game as Chelsea were pushing for an equaliser. Zubimendi finished the match with three interceptions, the most of any player on the pitch, despite only coming on in the 67th minute.
