Despite a bright start, the Black Cats fell a goal down in the 17th minute when defender Christian Kabesle headed home a corner.
Sunderland were then undone by another set-piece, as Ryan Porteous headed in another corner midway through the second half.
The hosts did manage to pull a goal back immediately when Luke O’Nien converted from close range in the 70th minute, before Patrick Roberts scored an excellent equaliser in stoppage-time.
Here’s how Phil Smith rated the Sunderland players against Watford:
The hosts did manage to pull a goal back immediately when Luke O’Nien converted from close range in the 70th minute, before Patrick Roberts scored an excellent equaliser in stoppage-time.