Jewison Bennette's late equaliser earned Sunderland a draw at Vicarage Road to deny Watford a fourth home win of the season.
Keinan Davis tapped in to put the Hornets ahead before Aji Alese equalised when his left-footed strike was judged to have crossed the line despite Hamza Choudhury's attempted clearance.
Ex-Hornet Luke O'Nien headed an attempted clearance into his own net to restore Watford's lead before Sunderland's Jack Clarke saw a fine finish ruled out for offside.
But Bennette rewarded the visitors' late onslaught when he controlled a ball on his chest and lashed in a low shot.