Troy Deeney's double put Watford on course for their second home win under new boss Nigel Pearson who is now a point away from equalling the same points total Quique Sanchez Flores achieved in his second spell at the club.
For Dean Smith, it's worrying times at the Aston Villa as his side are without an away win since October.
Ismaïla Sarr put the game out of Villa's reach even if the home side were playing with a numerical disadvantage for half an hour with Adrian Mariappa sent off earlier in the game after picking up two yellow cards.
Here's what we learnt...
Villa are in big trouble
There are now significant parallels with the awful 2015-16 campaign that saw Villa fall out of the Premier League for the first time in their history, and with only half a season played in their return to the top flight, their place is again under threat again.
A lack of Premier League experience throughout Villa's side has so far restricted Smith's side to only 18 points in their first 20 games. Confidence is also low with the worst away record in the league another factor in villas recent demise over the past two months.
Turf Moor is next up for Villa before a welcome break from league duties with Fulham in the FA Cup on Saturday.
Nigel Pearson's appointment has been timely ahead of a January window that promises to be a busy one for Watford. In a win over Manchester United and now Villa, with a good point at Sheffield United in between, Pearson has more than galvanised a squad of players capable of better.
Watford had scored just four goals at home before Pearson's arrival and were bottom of the table. Since then, Deeney has netted three in his last three starts.
Villa remain in 18th place after the loss at Watford, but with trips to Burnley and Brighton & Hove Albion coming up, and Manchester City looming next month, Smith will be targeting points on the road in what may prove to be a pivotal start to the new year.
Reinforcements in January will sanctioned but with FFP an issue for Villa, spending will be limited.