Henri Lansbury's first-half header proved enough to give Stuart Pearce's side another success over the previously unbeaten Owls, who put in a spirited bid to respond but found visiting goalkeeper Karl Darlow in fine form.
Almen Abdi finally wrapped up victory for the Hornets with his second strike in stoppage time after Troy Deeney and Keith Andrews had also netted, with Harry Bunn and Murray Wallace replying for the visitors.
Wolves are another team on 12 points following a 3-1 defeat of Blackburn at Molineux, with Bakary Sako bagging a brace after Nouha Dicko's opener for Wanderers, while Jordan Rhodes netted from the penalty spot for Rovers.
Norwich were denied a fourth straight Championship success, though, when Callum Wilson levelled for Bournemouth after Lewis Grabban had put the Canaries ahead against his old club in a 1-1 draw at Carrow Road.
Down at the other end of the table, Fulham picked up their first point of the season in a 1-1 stalemate with Cardiff. Tim Hoogland broke the deadlock for the Cottagers but Kenwyne Jones equalised for City.
However, beleaguered Blackpool still have nothing to show for their efforts this term after going down to a fifth straight loss at Millwall, with Scott McDonald and Scott Malone on target for the Lions before Nile Ranger netted for the Seasiders.
Wigan were the day's big winners in the second tier, with Callum McManaman hitting a double and Andrew Taylor and Martyn Waghorn also scoring in a 4-0 thrashing of Birmingham at the DW Stadium.
Lewis Dunk slammed in his second goal of the game three minutes into injury time as Brighton twice came from behind to draw 2-2 at home to Charlton, with Igor Vetokele bagging a brace for the Addicks.
Chris Martin put Derby ahead at home to Ipswich, but Christophe Berra levelled in a 1-1 draw, while Brentford won 2-0 at Rotherham after Andre Gray opened the scoring in first-half stoppage time and Nick Proschwitz wrapped up the victory in the 97th minute.
- Sports & Recreation
- Gabriel Tamas
- Stuart Pearce
- Troy Deeney
- Henri Lansbury
- Lewis Grabban
- Harry Bunn