In what was a frantic first half, Arsenal took the lead when a long hopeful ball over was not dealt with by Andreas Christensen, and his under-hit back pass was picked up by Nketiah, who finished expertly past Edouard Mendy for his first league goal of the season.
Much to the frustration of Arsenal boss Mikel Arteta, the lead did not last long as Chelsea were back on level terms just four minutes later. The Gunners wasted numerous chances to clear the ball before Werner’s strike deflected off Granit Xhaka to bring the scores level.
It was proving to be a difficult evening for both defences as Arsenal re-established their lead midway through the opening 45 minutes. Smith Rowe produced another fine finish to round off an excellent team goal, sweeping home into the bottom corner after excellent work from Xhaka and Martin Odegaard in the build-up.
The goals kept coming and the celebrations in the away end were cut short again as Chelsea hit back… again. Cesar Azpilicueta pounced like a striker to get on the end of Mason Mount’s ball into the box to take the two sides into the break on level terms.
Chelsea responded to their defensive frailties in the first half by bringing on Thiago Silva for Christensen, but it would be Arsenal who hit the front for a third time.
More indecision in the Chelsea defence allowed the striker to nip in and he poked home after Nuno Tavares’ cross had not been dealt with by the Blues’ backline.
Another frustrating night for Romelu Lukaku came to an end as Chelsea threw on Kai Havertz as they looked for a third equaliser of the night, but it never came.
Arsenal won a late penalty as Bukayo Saka was dragged to the ground by Azpilicueta, the forward dusting himself off to convert the resulting spot-kick to wrap up a crucial three points for the Gunners.