Match ends, Watford 2, Southampton 2.
Watford 2-2 Southampton
Abdoulaye Doucoure bundled home a controversial 90th-minute equaliser as Watford fought back from 2-0 down to draw with Southampton.
Doucoure used his right hand to divert Troy Deeney's header past Alex McCarthy from close range to snatch a point for the Hornets.
Two goals from James Ward-Prowse had given the Saints a 2-0 lead at half-time as they looked to be on course to end a run of nine Premier League games without a win.
But Watford came out stronger in the second half, thanks largely to the introduction of Deeney.
They pulled a goal back two minutes before the hour mark as Andre Gray headed home after McCarthy turned Daryl Janmaat's shot onto the crossbar.
Doucoure's late intervention meant the game finished all-square, but Watford have won just once in their past 10 Premier League games.
The home side edged an entertaining first quarter of an hour, but fell behind on 20 minutes as Shane Long's pull-back was deflected into the path of Ward-Prowse, who guided the ball into the bottom corner from 12 yards.
That turned the match in favour of the visitors, and they deservedly doubled their lead a minute before half-time. After Long's determined run down the left, he fed Dusan Tadic on the edge of the area and the Serb helped it on to Ward-Prowse, who netted past an exposed Heurelho Gomes.
The goals took Ward-Prowse's tally to three in his past two games, having failed to score this season before the FA Cup third-round win over Fulham last week.
Doucoure's 'clear handball' denies Saints at the last
Video assistant referees (VAR) made their debut in competitive English football this week - during Brighton's FA Cup win over Crystal Palace.
But - after three games in which referees have not had to draw an imaginary TV screen in the air with their fingers, then consult replays of controversial incidents - the system is not being trialled in the Premier League.
How Southampton must wish it was.
Television replays, available within seconds, showed Doucoure used his hand to provide the decisive touch - BBC Final Score pundit Kevin Kilbane describing it as a "clear handball".
"He's got his hand up by his head - it's as clear a handball as you're ever likely to see," he said. "It's a disgrace, an absolute disgrace. Southampton desperately needed this win, and they have been robbed. It's really poor."
- Read more: Where was VAR when it was needed?
- VAR signals set to be made clearer for fans before use in FA Cup replays
It could be argued Watford deserved their point based on their second-half performance, as Deeney showed what they have missed during his four-match suspension.
Prior to the break, the home side could not contain Long, Tadic and Ward-Prowse, but Deeney's introduction changed the game.
Pressure still on Pellegrino?
Southampton's first-half showing did not fit with a team that began the day outside of the relegation zone only on goal difference.
Watford deserve credit for their fightback but the Saints should have had more about them to avoid such a shift in momentum as they looked to avoid remaining winless in 10 consecutive league games for the first time since January 2005.
Some of that responsibility lies with manager Mauricio Pellegrino, who failed to react quickly enough to Watford adopting a more attacking formation when Deeney was introduced.
The draw lifts Saints up to 16th - ahead of Bournemouth on goal difference before the Cherries face Arsenal on Sunday - but questions remain about the future of Pellegrino.
Do the club's hierarchy want to put the £75m they received for the sale of defender Virgil van Dijk to Liverpool in his hands? Arsenal winger Theo Walcott and Atletico Madrid playmaker Nicolas Gaitan are said to be targets.
Man of the match - Shane Long (Southampton)
What the managers said
Southampton manager Mauricio Pellegrino: "I never see this type of mistake in the Premier League before. To live this injustice is really hard. I think we have to try [VAR] and analyse if it's possible to help the sport to make better decisions, even for the referee.
"Football is like this sometimes, small details change everything. We are very sad but we have to accept the rules. It's part of football. Even in the second half they were playing more direct, I don't remember many clear chances, just second balls. They are stronger than us in this physical battle.
"The last four games the team is growing. Playing in this way it's easy for everybody because I'm sure we'll win games."
Watford manager Marco Silva to Sky Sports: "I have a different opinion. I talk about the match, two different halves.
"I don't need to talk about the goal. Something can happen and this season we've had decisions go against us. I understand Southampton are unhappy like I was not one time, more than one time when the mistake is against us. It can happen."
Match stats - Fighting Hornets
- The Hornets have recovered eight points from losing positions at Vicarage Road in the Premier League this season - only Everton (9) have rescued more at home.
- Watford have conceded 25 goals at Vicarage Road in the Premier League this season - the most of any side in home games.
- Ward-Prowse scored his first double in the Premier League since January 2016 (v West Brom), which was his only previous one in the competition.
- Tadic recorded his 27th Premier League assist for Southampton - only Matt le Tissier (64) has made more for the Saints in the competition.
- Southampton conceded their 1,000th goal in the Premier League - becoming the seventh team in competition history to do so.
- Gray scored his first goal for Watford at Vicarage Road, in what is his 12th appearance there in all competitions for the Hornets.
- Doucoure has scored more goals (seven) and more home goals (four) than any other Watford player in the Premier League this season.
Watford travel to Leicester City on Saturday (15:00 GMT), while Southampton have an extra day to prepare for the visit of Tottenham (16:00 GMT).
The pair will meet again later this month in the fourth round of the FA Cup, this time at St Mary's on 27 January (15:00 GMT).
- 23WatsonSubstituted forDeeneyat 45'minutes
- 8CleverleySubstituted forPereyraat 35'minutes
- 18GraySubstituted forOkakaat 73'minutes
- 13McCarthyBooked at 81mins
- 2Cédric SoaresBooked at 90mins
- 14RomeuBooked at 79mins
- 23HøjbjergBooked at 31mins
- 16Ward-ProwseSubstituted forSimsat 90+3'minutes
- 11TadicBooked at 87minsSubstituted forBoufalat 90+2'minutes
- 8DavisSubstituted forLeminaat 63'minutes
- Roger East
- Shots on Target
Second Half ends, Watford 2, Southampton 2.
Foul by Daryl Janmaat (Watford).
Mario Lemina (Southampton) wins a free kick on the left wing.
Substitution, Southampton. Josh Sims replaces James Ward-Prowse.
Substitution, Southampton. Sofiane Boufal replaces Dusan Tadic.
Corner, Southampton. Conceded by Christian Kabasele.
Cédric Soares (Southampton) is shown the yellow card.
Goal! Watford 2, Southampton 2. Abdoulaye Doucouré (Watford) with an attempt from the centre of the box to the centre of the goal. Assisted by Troy Deeney with a headed pass.
Dusan Tadic (Southampton) is shown the yellow card.
Foul by Marvin Zeegelaar (Watford).
Shane Long (Southampton) wins a free kick on the right wing.
Foul by Christian Kabasele (Watford).
Shane Long (Southampton) wins a free kick in the attacking half.
Hand ball by Marvin Zeegelaar (Watford).
Foul by Molla Wagué (Watford).
Dusan Tadic (Southampton) wins a free kick on the left wing.
Alex McCarthy (Southampton) is shown the yellow card.
Oriol Romeu (Southampton) is shown the yellow card for a bad foul.
Stefano Okaka (Watford) wins a free kick in the defensive half.
Foul by Oriol Romeu (Southampton).
Attempt missed. Stefano Okaka (Watford) right footed shot from the centre of the box misses to the right. Assisted by Troy Deeney with a headed pass.
Abdoulaye Doucouré (Watford) wins a free kick in the defensive half.
Foul by Oriol Romeu (Southampton).
Foul by Stefano Okaka (Watford).
Wesley Hoedt (Southampton) wins a free kick in the defensive half.
Foul by Troy Deeney (Watford).
Jack Stephens (Southampton) wins a free kick in the defensive half.
Attempt missed. Daryl Janmaat (Watford) right footed shot from outside the box is high and wide to the right following a set piece situation.
Substitution, Watford. Stefano Okaka replaces Andre Gray.
Abdoulaye Doucouré (Watford) wins a free kick on the left wing.
Foul by Pierre-Emile Højbjerg (Southampton).
Attempt missed. Andre Gray (Watford) header from the centre of the box misses to the right. Assisted by Daryl Janmaat with a cross.
Attempt missed. Pierre-Emile Højbjerg (Southampton) header from the centre of the box is too high. Assisted by Ryan Bertrand.
Roberto Pereyra (Watford) wins a free kick in the defensive half.
Foul by Mario Lemina (Southampton).
Foul by Troy Deeney (Watford).
Oriol Romeu (Southampton) wins a free kick in the defensive half.
Delay over. They are ready to continue.
Delay in match Ryan Bertrand (Southampton) because of an injury.