Arsenal extended their unbeaten run to an 11th match as Emile Smith Rowe scored their second-half winner against Watford at the Emirates Stadium.
Smith Rowe fired the ball into the bottom corner after good work from Ben White though Watford were left unhappy that Arsenal didn't return the ball to them following a foul in the lead-up.
The Gunners were good value for the three points and should have led earlier with Pierre-Emerick Aubameyang seeing a first-half penalty kept out by Ben Foster.
Bukayo Saka had earlier seen a goal disallowed for offside and Aubameyang suffered a similar fate after the break.