Joao Pedro headed in a late winner as Watford consigned Wigan to a fourth-straight defeat.
The forward rose highest to meet Yaser Asprilla's cross to plant a fine header past Latics goalkeeper Jamie Jones.
Ismaila Sarr had gone closest in a goalless first half when he combined with Vakoun Bayo before his shot forced a point-blank save from Jones.
Will Keane's early long-range shot had forced Watford keeper Daniel Bachmann into a stop, but it proved their only attempt on target.
More to follow.