Eden Hazard set up the decisive goal for Marcos Alonso as Chelsea came out on top in a frenetic London derby.
For 20 minutes Chelsea were so good it looked like it would be a rout, with goals from Pedro and Alvaro Morata their reward.
But Arsenal roared back to level through Henrikh Mkhitaryan and Alex Iwobi within five first-half minutes.
Sportsmail's Sami Mokbel rated the players on Saturday.
Chelsea (4-3-3)
Kepa Arrizabalaga - Solid enough, but should have done better Mkhitarayan’s strike which squirmed past his right hand. 6
Cesar Azpilicueta - Dependable as ever and notched an assist for Morata’s first-half goal to boot. 7
Antonio Rudiger - Fast becoming a crowd favourite. Another all-action defensive performance by the Dutchman. 7
David Luiz - Looked entirely comfortable at the back until Arsenal’s unlikely response of scoring twice in four minutes in the first-half. 6.5
Marcos Alonso - A match-winning contribution. Assisted Pedro’s opener before emerging as Chelsea’s hero with late strike. 8
N’Golo Kante - Playing in a more advanced role, but the Frenchman was just as dynamic in Chelsea's midfield 7.5
Jorginho - Over 100 touches of the ball. The summer signing from Napoli looks every inch a top tier Premier League footballer. 8.5
Ross Barkley - Encouraging display from the midfielder. Looks fit and invigorated. Heavily involved until his substitution. 7
Willian - Started brightly but faded as Arsenal hit back. Replaced by Hazard in the 61st minute. 6
Alvaro Morata - His well taken goal should do him the world of good. Still plenty more in the locker, though. 7
Pedro - Kept his cool to put Chelsea ahead by by sweeping in an Alonso cross on the counter. A regular threat for the Blues. 7
Subs: Kovacic 6 (Barkley 60); Hazard 7.5 (Willian 60); Giroud 6 (Morata 75)
Subs not used: Caballero, Moses, Giroud, Christensen, Zappacosta.
Maurizio Sarri - Two wins from two. The early signs are promising for Chelsea’s latest boss. 7.5
Arsenal (4-2-3-1)
Petr Cech - Produced some good saves to ensure hung in there with a punchers chance. 7
Hector Bellerin - Went walkabout for Chelsea’s opener. Thrilling in attack but questions remain over defensive work. 5.5
Shkodran Mustafi - Feeble defending for Morata’s goal. Hasn’t lived up to his £30m price tag. Booked. 5
Sokratis - Recovered from Chelsea’s early onslaught to put in a solid enough display. 6.5
Nacho Monreal - Has hardly trained but his energy in closing down Willian created Arsenal’s key first goal. 6.5
Matteo Guendouzi - Looked lost in early stages but showed promising signs as he grew into the game. His passing was efficient. 7
Granit Xhaka - Gave the ball away with his first touch. Booked. Hooked at half-time. Oh dear. 4
Henrikh Mkhitaryan - The instigator of Arsenal’s surprising come back. A goal and an assist means - at least on a personal level - a satisfying day’s work. 8
Mesut Ozil - A passenger yet again. Emery was bold in hooking the German - but 100 percent the right decision. 4.5
Alex Iwobi - A surprise selection but justified his manager’s faith with a decisive contribution. 7.5
Pierre-Emerick Aubameyang - Missed some glorious opportunities. Arsenal could have been out of sight had he been more clinical. 6
Subs: Torreira 6 (Xhaka 46); Ramsey 6 (Ozil 68); Lacazette 5.5 (Iwobi 75)
Unai Emery - Will be encouraged by his team’s comeback. But fact remains that it’s two defeats from two in the post-Wenger era. 6.5
Subs: Leno, Elneny, Welbeck, Lichsteiner
Referee - Martin Atkinson - 6.5
Att: 40, 491
MOM: Jorginho