It was a relatively uneventful first half with Arsenal striker Gabriel Jesus having the best chance of the half.
But barely twenty minutes into the second half, Chelsea, coached by Graham Potter, had to give up.
The Chelsea defense didn't get hold of Martin Ödegaard's corner, but it instead reached Gabriel, who kicked it in from close range.
Shortly after that, former Arsenal star Pierre-Emerick Aubameyang, now at Chelsea, was also replaced.
With less than ten minutes of regular time remaining, Arsenal wanted a penalty for a handball on Marc Cucurella, but after video review it was not to be.
In added time, Arsenal's Granit Xhaka and Chelsea's Trevoh Chalobah got into a fight.
Several of their teammates joined in the brawl.
The match ended 1-0 and Arsenal remain leaders in the Premier League.
Chelsea are in seventh place, 13 points behind their rivals.