Abdoulaye Doucoure scored a controversial last-minute equaliser to secure a 2-2 draw for Watford as Southampton's Premier League winless run was extended to 10 matches.
A first-half double from James Ward-Prowse had put the Saints in the driving seat, but Andre Gray cut the deficit early in the second half and Doucoure got the leveller at the death, appearing to use his hand to do so.
It added to Mauricio Pellegrino's misery as his side's poor form continued, though Watford themselves have won just once over same period of Saints' top-flight winless streak.
Having opened his account for the season in last weekend's FA Cup win over Fulham – setting up a fourth-round clash with the Hornets – Ward-Prowse picked up where he left off.
The midfielder broke the deadlock after 20 minutes as Southampton sought revenge for September's 2-0 loss to the same opponents at St Mary's Stadium.
Pellegrino's men continued to impose themselves on the game and, after Dusan Tadic and Wesley Hoedt had been thwarted by Heurelho Gomes, Ward-Prowse was on hand again to cap a swift counter-attack with a straightforward finish.
Watford fought back after the break, with Gray nodding in and Doucoure stealing the headlines in more ways than one, leaving the visitors to wish VAR was in use.
FT | #watfordfc 2-2 Southampton— Watford FC (@WatfordFC) January 13, 2018
Gray and Doucoure goals after the break peg back the Saints, who led via a first-half Ward-Prowse double. #WATSOU
Listen live https ://t.co/MVTxcdM2TV pic.twitter.com/G7X6pENKv4
Southampton threatened early on but saw a promising attack ended by an offside flag as Shane Long's shot forced a reflex save from Gomes.
The hosts badly fluffed their lines to ensure a dangerous foray into the Saints box yielded no reward, with Doucoure's cutback miskicked by Gray before Daryl Janmaat's follow up was blocked, the same player then flashing a powerful drive just over the crossbar.
But, having failed to make that pressure count, the Hornets were punished at the other end when Ward-Prowse coolly slotted home from inside the box after good work from Long.
Gomes came to Watford's rescue to deny Tadic a certain goal three minutes later, the Brazilian pawing away the midfielder's back-post header.
A speculative Hoedt effort from long range gave Gomes yet more work to do and he was equal to it, as was Marvin Zeegelaar when the Dutchman had to block Long's attempt from the edge of the six-yard box.
But there was nobody there to save Silva's side when Long burst down the left to pick out Tadic, who in turn laid on a simple finish for Ward-Prowse.
Troy Deeney was introduced at the interval, marking his return to league action after a four-match ban following his dismissal against Huddersfield Town last month.
A much-improved Watford started to show signs of life early in the second half and Richarlison had a shot blocked before finally they got their reward after 58 minutes.
Janmaat's rasping drive was tipped onto the bar by Alex McCarthy, who got no help from his defence when the ball fell for an unchallenged Gray to nod in.
Molla Wague then mistimed his jump when well positioned to connect with substitute Roberto Pereyra’s delivery as Watford continued to turn the screw.
Pellegrino sent on Mario Lemina as he looked to stem the tide and Southampton did initially stabilise, helping to quieten the expectant home crowd until Doucoure had the final say, turning in Deeney's header across goal and evading the attentions of referee Roger East.
Key Opta stats:
- The Hornets have recovered eight points from losing positions at Vicarage Road in the Premier League this term – only Everton (9) have rescued more on home soil.
- Southampton are winless in their last 10 games in the Premier League; their longest run without a win in the competition since January 2005 (also 10 games).
- Watford have conceded 25 goals at Vicarage Road in the Premier League this season – the most of any side in home games.
- Dusan Tadic recorded his 27th Premier League assist for Southampton in this game – only Matt Le Tissier (64) has made more for the Saints in the competition.
- Southampton conceded their 1000th goal in the Premier League following Watford’s equaliser – becoming the seventh team in competition history to do so.
|Ruud awakening for Ferrer in Bastad|
|Nibali withdraws from Tour de France with back fracture|
|Fabinho: I´ll try to convince Mbappe to join Liverpool|
|Beating Messi boosted France´s World Cup belief – Lloris|
|Carnoustie saving the worst until last|
|McIlroy´s youthful exuberance could be a bad sign for Carnoustie contenders|
|Saints triumph at second-placed Wigan|
|Anfield atmosphere sweetened Alisson on Liverpool|
|Bouchard reaches Gstaad quarter-finals|
|´What are you waiting for?´ - Alisson reveals Salah text messages|
|´Full package´ Alisson could not be missed - Klopp|
|Alisson to Liverpool: Brazil star becomes most expensive goalkeeper in history|
|Alisson to Liverpool: Brazilian´s stats blitz Mignolet, Karius|
|Liverpool sign Alisson in world-record deal|
|The Open 2018 diary: Spieth´s got ball skills as Finau proves the scratch golfer|
|Woods: Score doesn´t reflect how well I played|
|Can we go to Paris now? - Thomas in a hurry after conquering Alpe d´Huez|
|Thomas: I could have finished stronger|
|Kisner shines at baked Carnoustie as McIlroy, Rahm and Thomas loom|
|Sarri´s mentality made me a better footballer - Jorginho|
|Tax rates played a role in Ronaldo joining Juventus, says LaLiga president|
|Aggressive McIlroy doing it his way, not the fairway|
|I let him have it - Spinazzola ribs Ronaldo over Juve shirt number|
|Thomas makes it back-to-back wins|
|Ramos may remain for Spain but Luis Enrique promising surprises|
|Cazorla still playing through pain after Villarreal appearance|
|Vegas to Carnoustie - a hellish trip for Jhonattan|
|NFL training camp 2018: Five under-the-radar rookies to watch|
|Woods off to a flyer as Thomas charges|
|Sanchez given green light to join Man Utd tour|
|Greipel, Groenewegen and Gaviria latest sprinters to abandon Tour de France|
|Luis Enrique hopeful over Pique as he plots a Spanish evolution|
|I had a brain fart - Spieth disappointed with missed opportunity|
|I´ve sacrificed too much to quit, says injury-plagued Rossi|
|Klopp rejects Henderson´s plea to return early to Liverpool training|
|Open champion Spieth loses ground in scrappy finish|
|Alexis Sanchez hints visa issue sorted as United States trip beckons|
|Kovac an admirer of Pavard, expects James to stay|
|Dzeko happy at Roma and eyeing silverware|
|Eels win basement battle with Bulldogs|
|Kluivert to follow Totti´s example after taking ´big step´ with Roma|
|Kisner hopes to return Claret Jug favour to Spieth|
|FIBA bans 13 players & two coaches over Philippines-Australia brawl|
|Spieth and Rahm in the mix as Kisner sets the target|
|Monchi insists Roma remain ambitious as Liverpool close in on Alisson|
|Cavendish thanks ´race that shaped career & heart´ after cruel Tour exit|
|No Trent Bridge Ashes Test as England confirm schedule|
|Ajax tell Barcelona not even ´insane´ money will buy De Ligt, De Jong|
|Hamilton agrees two-year Mercedes extension|
|Uran withdraws from Tour after failing to shake off injuries|
|Spieth tees off Open defence|
|Zidane has shown no will to coach France, insists FFF president|
|Risking the curse - Steelers star Brown lands on Madden 19 cover|
|Pogba silenced his critics with World Cup displays – Ibrahimovic|
|Warburton overwhelmed by support following retirement|
|Wilshere excited by tactics of Wenger-like Pellegrini|
|Deschamps never considered France exit prior to World Cup win|
|Persepolis eye Champions League after Iran impress at World Cup|
|Sandy Lyle gets The Open underway at Carnoustie|
|Roosters sign England international Hall|
|Ovechkin, Kim earn major honours at ESPY Awards|
|Owens not ´actively seeking´ to play in NFL again|
|Argentina need Messi – Tevez urges Lionel not to retire|
|Minnesota United 2 New England Revolution 1: Ramirez, Quintero sink stuttering visitors|
|Shaw: I want to be first name on Man United teamsheet|
|Manny Machado dealt to Dodgers|
|Pjanic hails Ronaldo arrival but refuses to confirm Juve future|
|Perotti: Roma can cope without Liverpool-bound Alisson|
|Klopp hopes Liverpool building towards title tilt|
|Karlovic exits as four seeds bow out in Newport|