The blues were largely dominant throughout and never looked likely to surrender the lead once the opening goal came their way.
Olivier Giroud scored the opener after some fine approach play, with Willian then converting a penalty after Christian Pulisic had been fouled.
Watford only briefly threatened very late in the match and Ross Barkley ended the night with a late third for Chelsea as they moved back into fourth in the table.
Here are five things we learned from the game at Stamford Bridge.
Lampard sets the standards
After a disappointing 3-2 loss at West Ham last time out, it wasn’t a surprise to see Frank Lampard make changes to his lineup.
He spoke before and after that game about the need for consistency and concentration in all types of games—and the alternations to his team here were a clear indication that he requires higher standards in his first-choice lineup.
Kurt Zouma, Reece James and Mason Mount were all given opportunities to start and each offered positives to the performance and reasons for the manager to keep faith with them next time.
There’s a fine line to tread between managers trusting their players and letting them know that better is expected, and Chelsea’s boss looks to have got it right on this occasion.
Duo still have plenty to offer
With Timo Werner and Hakim Ziyech already signed up for next season, the attacking options will be vast for Lampard in future.
But two players on the night showed that they have much they can still bring to the team, despite a suggestion they may be the ones to make way – for different reasons.
Willian is out of contract and set to depart, unless he and the club come to an agreement over the length of a possible extension.
He has been free-scoring since the restart and was brilliant against Watford, showing great link-up play, an awareness of space, clever touches and a willingness to shoot with regularity.
Mason Mount has a huge future, but some suspect he may be squeezed out early on in 2020/21—but playing in a deeper midfield role he pulled the strings, worked hard and had the moment of precise ingenuity which created the opening goal thanks to a through-pass to the eventual assist provider, Ross Barkley.
Watford concerns continue to grow
Three shots on target for Watford—all late on, two of which were long-range strikes from substitute left-back Adam Masina.
And that comes on the back of a home defeat to Southampton where they had no shots on target at all, with an own goal their only reward.
Given their precarious position, one place and one point above the relegation zone, it’s not hard to work out where the improvements need to come—and quickly.
Watford have five games left to save themselves and they simply have to find the answers in how to improve their build-up play before their next game: at home, to bottom club Norwich.
While Willian may depart and Mount will face a fight for game time, Christian Pulisic is doing all he can to prove he should be a guaranteed starter.
The American has had an up-and-down season at times but, when fit, has had the consistency and end product which will make him difficult to leave out.
Werner has often been at his best for Leipzig on the left side of a three-man attack—but that’s precisely where Pulisic has been best for Chelsea and he was again a constant menace with his pace, dribbling and willingness to shoot.
He won a penalty, might have had a goal or two of his own on another night and generally terrorised the Hornets’ back line with plenty of guile, close control and aggression in his running.
Chelsea’s attacking options next season will be frightening indeed.
Champions League spot still in Chelsea’s hands
After Manchester United’s thumping win over Bournemouth earlier in the day, Chelsea were briefly outside of the Champions League spots.
This win, then, was important on multiple fronts: it’s another game closer to the end of the season, it’s an indication that they have the mentality to handle pressure and, most importantly, it leaves their fate in their own hands.
Finishing fifth may yet be enough to qualify, depending on Manchester City’s ban and appeal, but clubs cannot rely on that decision alone.
Chelsea are back into fourth after this victory, one point behind third-place Leicester again, and the race for the guaranteed European spots remains fierce.