Arsenal again produced a contrasting performance to throw away a two-goal lead at Watford on Quique Sanches Flores’ return to Vicarage Road.
The Gunners looked good value for victory at half-time, after Pierre-Emerick Aubameyang’s first-half double.
But in the second half, the away side fell apart as Flores’ men fought back.
A dismal error from Sokratis handed Tom Cleverley the chance to reduce the arrears early in the second period, and the ex-Manchester United and Everton midfielder fired home.
Then, with just under 10 minutes to go, David Luiz decided to press his self destruct button, dangling a leg and bringing down Roberto Pereyra needlessly, with the Argentine scoring from the spot.
Out on their feet, Arsenal almost lost it in injury time, only for Bernd Leno to deny Abdoulaye Doucoure following a sweeping counter-attack.