A late strike from substitute Cristian Battocchio fired Watford to their third straight Championship win as they overcame Wigan in a tight contest.
Italian Under-21 midfielder Battocchio lashed home from the edge of the area with eight minutes remaining after Davide Faraoni's shot was blocked.
In a game of few chances, Wigan were frustrated when Nick Powell's strike was ruled out for offside.
Powell and James McClean then missed chances as the hosts ground out a win.
Watford started brightly and had the first good chance when Daniel Pudil's side-footed effort was saved by Latics keeper Scott Carson.
Soon afterwards Powell had the ball in the net for Wigan, but the goal was ruled out for a marginal offside decision.
The tempo of the game dropped for the rest of the first half, but the Hornets tried to up the pace after the break as Fernando Forestieri and Lewis McGugan had shots blocked.
Watford keeper Manuel Almunia made a smart double save, first to foil Powell and then McClean on the rebound, to deny the visitors.
Wigan boss Owen Coyle felt his side should have won a penalty when Lloyd Doyley tangled with Powell in the box, and his mood worsened when the Latics fell behind.
The goal arrived when substitute Faraoni's strike cannoned to the edge of the penalty area, where Battocchio placed a right-footed shot past the unsighted Carson.
Diego Fabbrini almost added a second in injury-time, but his powerful strike across goal was tipped away by the Latics keeper.
Watford manager Gianfranco Zola:
"It was a typical game between two top teams where the values of the teams are very similar, so there's a kind of equilibrium on the pitch and you just have to be patient, keep working hard and wait for your opportunity to come.
"That's exactly what happened today. Don't forget also it was the fifth game in two weeks and that counts, so the quality of the game cannot be fantastic.
"But we showed a lot of character to win this game and that is something that will be very important from now until the end of the season."
Wigan manager Owen Coyle:
"We were terrific today. Watford are a very good side and will challenge - as we will - to get back to the Premier League, but to come here and give the level of performance we did with our fourth game in nine days, the players were an absolute credit.
"We scored a perfectly good goal - I don't envy the referee, or the officials, their job. At this level we understand little fouls sometimes you'll get, sometimes you won't - but you've got to get the major decisions right."