Pierre-Emerick Aubameyang's deadly finishing, in the absence of the injured Alexandre Lacazette, looked to have steered Arsenal to victory after the Gabon international netted twice in 11 first-half minutes to take his tally to five in five Premier League games this season.

Unai Emery's men took the lead when Will Hughes was bundled off the ball and Aubameyang finished off a fast break with a cool finish, and the second arrived soon after courtesy of an astute Mesut Ozil through-ball.

But Arsenal came under heavy pressure in the opening stages of both halves of an entertaining encounter and Watford pulled one back after a calamitous pass from Sokratis allowed Tom Cleverley a chance that he buried with aplomb.

David Luiz conceded a penalty nine minutes from time that substitute Roberto Pereyra confidently converted.

Arsenal, which came from behind to draw 2-2 with Tottenham in its last outing, is winless in three Premier League games, while Sanchez Flores doubled Watford's points tally for the season by guiding it to a draw.