Ben Foster came so close to clinching a dramatic draw for Watford, but it was what happened earlier the second half that this evening’s 2-1 defeat to Chelsea will be remembered for – and may have ongoing consequences.

The Hornets were trailing 2-0 when Quique Sanchez Flores made his final change and brought on Kiko Femenia for Daryl Janmaat instead of deploying the more attacking Isaac Success. Many of the home faithful turned on the head coach, booing the decision with chants of ‘you don’t know what you’re doing’ ringing out.

Within five minutes though, Watford were handed a lifeline when Gerard Deulofeu converted a penalty controversially, and farcically, awarded by VAR official Mike Dean.

That increasingly looked like being a consolation though, until deep into injury time when a Deulofeu free-kick was flicked on and Foster headed goalwards, only to be superbly thwarted by Kepa Arrizabalaga.

The game got off to the worst of starts for the hosts who conceded after barely four minutes when Tammy Abraham made the most of a superb pass from Jorginho, allied with some dismal defending, to give Chelsea the early lead.

After Foster had made two good saves to keep the gap at one, the Hornets started to play with a little more belief. While the quality remained in relatively short supply, there was at least more purpose and vigour about their attacking advances, with Andre Gray inches away from turning a Deulofeu driven effort into the net.

Foster made two more top-class saves either side of half-time, but when Christian Pulisic converted Chelsea’s second 10 minutes after the break it looked to be a case of game over until the last quarter of the match.

Both sides had seen their League Cup hopes end for the season in midweek, but it was a case of one change apiece to their starting line-ups from their respective last league outings.

Gray replaced the injured Tom Cleverley in the only alteration to the Hornets’ side from the goalless draw with Bournemouth.

The Blues continued their good run of top-flight form with a 4-2 triumph at Burnley last time out and Frank Lampard’s sole change was to bring in Emerson Palmieri for Marcos Alonso at left-back.

The Hornets lined-up in a 5-4-1 formation when defending, but they were content to let their opponents have the majority of the ball in the early stages in areas where they couldn’t hurt them. That changed with barely four minutes on the clock.

Jorginho was the creator with an admittedly superb 40-yard pass but Craig Dawson was not alive to the danger as Abraham ran in behind off the back of the Hornets centre-half and clipped a finish past the exposed Foster, who had hesitated in coming out, to give the Blues the early lead.

Mason Mount struck an ambitious free-kick over the top soon after, but with the early breakthrough under their belts Chelsea were content to knock the ball around at will – and in the face of not a great deal of pressure.

The bad start got even worse for the Hornets in the 12th minute when their injury curse struck again, this time Craig Cathcart was the victim. While Adrian Mariappa was being readied to come on though, there was a chink of light for the hosts when a shooting opportunity opened up for Roberto Pereyra after Chelsea had made a hash of clearing a Daryl Janmaat delivery, but the Argentinian’s curled effort was straight at Arrizabalaga.

That only served to spark the Blues back into life and they almost scored a second twice in quick succession.

First, a Mount shot broke invitingly for Abraham in the area and he attempted to place a finish to the left of Foster, but the Hornets keeper was equal to it and the ball was then put behind for a corner.

Willian took the set piece from the right and clipped the ball into the near post area where Pulisic got the jump on Nathaniel Chalobah with too much ease, but the American’s looping header again could not get the better of Foster as he made a superb arcing save to keep it out.

Cathcart’s evening finally came to a premature end in the 20th minute when he was replaced by Mariappa, but that was to signal the start of a period when the hosts attacked with at least more purpose and vigour which in turn got the Hornets fans going.

The home faithful weren’t far away from cheering an equaliser in the 39th minute when after a Deulofeu corner from the right was half cleared, Chalobah knocked the ball back to the Spaniard who cut inside from the left before driving a low left-footed shot narrowly wide of the far post. However, replays showed Gray was a hair’s breath away from getting a touch on the ball en route and surely diverting it into the net.

Having come close to being pegged back though, Chelsea were even closer to taking a two-goal lead into the break when Mount drove infield off the left and struck a fine right-footed curling effort which Foster got enough of a touch on to turn the ball onto the bar.

The second period started with the first booking of the evening, Christian Kabasele receiving it for a clear trip on Emerson.

Within a minute though, the Hornets were bursting forward when Janmaat intercepted a pass on the right and teed up Deulofeu who attacked the area before slipping a pass sideways to Gray, but Kurt Zouma flung himself in front of the ball to block the shot.

Seeking an equaliser brings dangers and the hosts were almost caught on the counter soon after when Willian attacked at pace before passing the ball to his left where Mount hit a first-time effort towards the top corner, but again Foster was equal to it with his latest fine save of the contest.

But there was nothing the Hornets keeper could do in the 54th minute when Chelsea doubled their lead with relative ease.

Willian was afforded far too much space when he received the ball in a central area and was able to pass it to the right side of the area where Abraham played in a low first-time delivery and Pulisic burst into the six-yard box to side-foot home.

The American very nearly doubled his tally soon after, accelerating away from Janmaat on the left side of the area and riding a challenge, only to see his attempted finish from a tight angle kept out by the outstretched leg of Foster.

The keeper had a more routine save to hold onto a Mateo Kovacic shot from outside the box as Chelsea looked to kill the game, their next chance coming when Abraham was close to connecting with another effort from the midfielder.

Will Hughes replaced Chalobah after 67 minutes before Mariappa did well to prevent Abraham having a clear effort from close range.

Emerson was fortunate not to be booked for what looked to be a dive in the Hornets box, but Anthony Taylor did decide a yellow card was necessary when the left-back was fouled by Janmaat moments later.

It was the Dutchman who made way when Sanchez Flores made his final change five minutes, but with the Hornets 2-0 down the sight of Femenia replacing him was not what the home fans wanted. They responded with a chorus of boos and chants of ‘you don’t know what you’re doing. The atmosphere had turned.

Within five minutes though, the Watford supporters had something to cling onto again when their side were handed a lifeline as the latest VAR farce unfolded.

Deulofeu appealed more in hope than expectation when he was challenged by Jorginho in the area, but it was checked by VAR.

Any contact was minimal but after the replay was shown numerous times, VAR official Dean decided to recommend a spot-kick was awarded – Taylor pointedly did not go across to the monitor to check himself – and Deulofeu duly converted from 12 yards to give his side hope.

Lampard made a couple of late changes as Chelsea tried to take the sting out of the game, and for the most part they succeeded as the home side were frustrated in their efforts to try and get the equaliser, until injury time. But the closest they looking like coming was when Adam Masina headed a deep Femenia cross well wide of the far post.

Then there was almost one dramatic last twist.

Watford were awarded a free-kick in a central position around 40 yards and with nothing left to lose Foster ventured forward.

Deulofeu delivered the free-kick towards the penalty spot, Abdoulaye Doucuoure flicked it on and Foster met it with a diving header that was destined for the bottom corner until Arrizabalaga plunged to his left to push the ball behind.

The Hornets had come so close to a draw but it was a game that is more likely to be remembered, and discussed, for two decisions that happened earlier in the second half.

Watford: Foster; Janmaat (Femenia 75), Kabasele, Dawson, Cathcart (Mariappa 20), Masina; Deulofeu, Doucoure, Chalobah (Hughes 67), Pereyra; Gray. Subs not used: Gomes, Success, Holebas, Foulquier.

Chelsea: Arrizabalaga; Azpilicueta, Zouma, Tomori, Emerson; Jorginho, Kovacic; Willian (James 90), Mount, Pulisic (Hudson-Odoi 83); Abraham (Batshauyi 87). Subs not used: Caballero, Alonso, Giroud, Gilmour.

Referee: Anthony Taylor.