Arsenal scored with their first three attempts on target, Aubameyang getting the first with a penalty after Craig Dawson’s clumsy foul on Alexandre Lacazette inside the opening minute.
Scotland defender Kieran Tierney doubled the lead after Aubameyang’s assist before the Gabon forward’s classy overhead kick – his 22nd league goal of the season.
Watford pulled a goal back from the penalty spot through Troy Deeney after David Luiz’s foul on former Gunners forward Danny Welbeck, who then made it 3-2 from close range.
Arsenal XI: Martínez, Maitland-Niles, Holding, David Luiz, Tierney, Ceballos, Xhaka, Pépé, Willock, Aubameyang, Lacazette
Subs: Papastathopoulos, Torreira, Cédric Soares, Nelson, Nketiah, Kolasinac, Macey, Smith, Saka
Watford XI: Foster, Femenía, Dawson, Kabasele, Masina, Hughes, Doucouré, Sarr, Pereyra, Welbeck, Deeney
Subs: Gomes, Mariappa, Cleverley, Chalobah, Cathcart, João Pedro, Gray, Quina, Pussetto