Pressure on under-fire Chelsea boss Antonio Conte intensified after they crashed to a heavy defeat at Vicarage Road.
Eden Hazard's superb solo effort had looked like earning the 10-man Blues a point after he cancelled out Troy Deeney's first-half penalty.
However, Janmaat put the Hornets back in front soon after before Gerard Deulofeu and Roberto Pereyra wrapped up victory for the hosts.
Conte's side were force to play more than an hour a man short after Tiemoue Bakayoko was given his marching orders for a second booking.
Here's five talking points from the game:
1. If Bakayoko is the answer, what was the question?
It is fair to say Tiemoue Bakayoko has yet to win over Chelsea fans since his £40 million move from Monaco last summer.
And his red card, after a mistake-riddled half-hour at Vicarage Road, will do nothing to help sway the jury's deliberations.
Bakayoko can have few complaints after his two bookings, five minutes apart, for poor challenges on Etienne Capoue and Richarlison.
Neither challenge was outrageous, but both smacked of a player yet to come to terms with the Premier League's relentless physicality.
2. Don't cock the firing pin yet, Roman
According to the Ministry of Mischief, all is not well behind the scenes at Chelsea and manager Antonio Conte is in the frame to get his old job back as Italy's national coach.
Owner Roman Abramovich has exercised his trigger finger at this stage of the season before, notably in disposing of 'Phil' Scolari nine years ago and Andre Villas-Boas in 2012.
But later this month, Conte should get a chance to knock Barcelona off their perch in the Champions League when Lionel Messi and Luis Suarez come to Stamford Bridge in the last 16.
And no disrespect to Hull City, but a place in the FA Cup quarter-finals is there for the taking nect week.
Even the greediest, most gluttonous owners would normally settle for two trophies and a top-four finish.
If there was any doubt about the loyalty to their leader among travelling disciples from west London, they broke into noisy support for Conte in the opening seconds.
3. Worst Hammy United
David Luiz started his first Premier League since October 28 and didn't look as though he enjoyed the experience.
Chelsea were forced to rearrange the furniture after wing-back Marcos Alonso was ruled out with a “slight” strain, adding to the colossal injury list which has left Conte's high-intensity training methods under the spotlight.
Currently there are seven confirmed cases of twanged hamstrings at Stamford Bridge, and Ross Barkley – who joined the sicknotes last week – is believed to be the eighth victim of Chelsea's hammy curse.
4. Blue is the colour for Richarlison
Watford's Brazilian discovery Richarlison has revealed he regularly goes round to Chelsea defender David Luiz's house for barbecues and to exercise his thumbs on the PlayStation console.
Another Chelsea player, Willian, often makes up a holy trilogy of Brazilians, and it would be no surprise to see all three on the same side in the Premier League next season.
Richarlison was unimpressed when the Hornets sacked head coach Marco Silva last month, admitting: “Marco is the person who is least to blame (for bad results) but he was the one who paid the highest price. The ones on the pitch were the players, not him.”
5. Watford fans believe in Gino
Just in case there are any non-believers out there who haven't yet got the message: Watford fans back owner Gino Pozzo's decision to fire Marco Silva 15 days ago.
Not for the first time, Hornets diehards in the Rookery unfurled an industrial-size banner bearing an image of the Harvard-educated Italian, who is now on to his 10th head coach in fewer than six years at Vicarage Road.
The players decorated Javi Gracia's first home game in charge with a first half brimming with endeavour. If those 45 minutes continue to be the yardstick, Watford won't go down.
Namor_3110
132
Chelsea upcoming fixtures UCL: Barcelona PL: Man Utd UCL Barcelona PL: Man City Chelsea fans grab ur coats. Winter is coming😂😂
arnav08
111
This was really shocking. & Conte is in even more serious trouble now. After Hazard's equaliser a draw was expected but Watford just went on thrashing & clinched it. Champions league R16 is coming up & this sort of performance will surely see the exit of Chelsea in the hands of Barcelona. Chelsea needs to rectify its mistakes & show its superiority. Hope that Chelsea will learn from the recent defeat & come back strong 💪 💪.
Felix1677
108
Its not Conte Is just that Chelsea players dont want to play for Conte anymore and they did the same thing to Jose Mourinho 2 years ago and the are doing it now to Conte and they do not care about how the fans feel about Their Performance so stop blaming Conte cuz Chelsea PLAYERS are childish
k2samuelkeita
94
Now conté have realized the intensity of the premier league. he was only lucky to come last season and walk away with the title and this happens because that was a transitional season Leicester took the title and they were planning to retain it, city got a new manager united and Chelsea as well now it is counted on him he should know that Chelsea players are like Judas Iscariot if they want Roman to kill him like the way they killed mourinho they can do and more worse if they realized they have nothing on hand
Armathon24
61
Conte is in under pressure. They don't have quantity squad. But quality players are also not doing there job. Worst performance by Chelsea. Conceded 3 goals in 2nd half. Bakayoko was not good. Sent off. Chelsea has to think about Conte now.
Doctor Ok
51
I don't think it would be prudent to blame Conte, the Italian proved himself when he got the domestic cup Last season. Conte simply doesn't have control over the squad, who to bring in or to loan or even bench!!! The personal assistant of the owner brings quantity rather than quality so honestly who would coach such a team??!! Conte still tries to keep a champions league place and if he successfully does that even without silverware he would be among the best still. Chelsea ownership should realize that if you employ a driver you also must give them the car keys
joudenstuz
32
Cahil hv to go especially when Conte leave Chelsea. Bakayoko n Zanacosta to be loaned out for the rest of their contracts. Chelsea need to get serious wth its markets negociations. Conte z a good coach, only the media that put so much pressure on him.
Đaiveed ♥
24
Conte is a good Coach it's not he's fault for what's currently happening to Chelsea it's football it's not every time you play a good game and win.. some of the players aren't reliable again they can't perform well as they used to before, lack of some potential signing.. Chelsea had the money to sign some potential players like Eden dzeko and the rest but they just failed at getting them.. The players need to be focused and work hard as a United Team, cooperation should exist between the players when they play games, conte should make some possible adjustments to the Team, he should bring on Emerson he's a talented player can't wait to see how far he would strengthen their defence and hopefully prevent them from conceding lots of goals,i think with this Chelsea would be able to get back to their good Club.. He's a very good coach and it's not an easy job coaching a team like Chelsea one of the Best clubs in the World, so give him sometime the fans and Board needs to be patient and support the Club at all cost I think with they can get useful game results.
TrippleK
24
Conte in big trouble and because he knows how to humiliate his opponents with excessive celebrations now is time for him to taste the same pill.
fuscdelps
21
All in all I do not think Antonio Conte is to blame for all this rubbish taking place at the Stamford Bridge. Chelsea is one club that does not show any support for the Manager no matter how good he has done for the ckub and we have all seen it. funny enough there's nothing we do. I don't think they have ever given Conte any signing that he asked for and when things get sour they chop the manager. 1. The manager should only have issues with player because he can solve that and not with the Senior administration staffs. Michael Emenalo Maria Granovaskia or whatever her name is I don't care and Antonio Conte were not speaking with each other but their job required them to communicate. what happened Emenalo resigned and we don't have a serious technical director or scout since then. 2.Conte has never ever had any played he asked for but the club goes for second option. Conte asked for Belloti, they Brought him Morata not Bad though. He asked for Sandro non came through except for Zapacosta. He asked for Verrati they brought him Bakayoko/Backley. 3. They don't talk to him but instead send him emails on matters that are supposed to be discussed in the meetings.
uwaa
18
sometimes be careful of what you say or do I remember when Conte was ranting that he is not here to make everyone happy all he cares about is winning but he forgot that it is those players will give him the results am still waiting for the news of his sacking
Suche
15
not bakayoko problem... i think... ref problem.. cannot see what bakoyoko doing.. i think that is not red card...first have only u give red card.. good refferrrryyyyshhiit
Same as l thought. The referees sometimes influences the game. Though Babayako is not playing well but a red card on not so serious challenge is annoying. Some players have gotten the worst kicks yet the referees issue a yellow card or even ignore it. It was too early for the red card. This greatly affected the outcome of the game.
jakirocitizen
14
SHAME ON U CHELSEA ..... no one can believe if I said Chelsea was champions of last season .....people will Laugh on me
Africa6120591
13
I trust in my club. All we need is a strong striker that does not miss it target
Forget that he won the league. Check Chelsea's antecedents for the past few years now & you will discover that any season Chelsea struggle in the league the players do play with their all & best the following season. Conte came when the players were very much in shape & willing to fight to win every game & they did just that with sharp Striker in Diego Costa being a big plus for him(Conte) to work with that helped him win the league. So he didn't win the league then because he was that exceptional as a Coach, but because he had the players in good shape & fighting Spirit. Teams understand Conte's formation very well now & the left & right back in Alonso & Moses now struggle to make the usual differences in game. & Moses can be use as a winger as the main wing he plays normally & he is kinda tired of that defensive pattern he has been forced to. Conte has no plan B as it is. See him against Arsenal severally. His record in Italy shows this too. That's just the reason for the poor performance this season. Conte need to motivate his players with good relationship & encourage them to win games.