Ché Adams followed up his midweek strike in the Carabao Cup with his first Premier League goal of the season to secure a crucial victory for Southampton at Watford.
The only goal of the game arrived 20 minutes into a first half Saints dominated; a precise curling shot into the top corner fit to win any match.
Adams and strike partner Adam Armstrong might have extended the margin of victory, while Alex McCarthy made a vital late save to preserve another welcome clean sheet.
As expected, Ralph Hasenhüttl made wholesale changes after the midweek Carabao Cup tie at Chelsea, but also four alterations from the last league game, a 2-2 home draw with Burnley.
James Ward-Prowse returned from suspension to captain the side, Kyle Walker-Peters was preferred to Romain Perraud up against Watford danger man Ismaila Sarr, and the pairing of Adams and Armstrong was restored in the absence of Armando Broja through injury.
It’s two and a half years since Shane Long made history by scoring the Premier League’s fastest ever goal, and Saints were straight on the front foot at Vicarage Road, as Nathan Redmond’s low cross was inadvertently turned goalwards by defender Craig Cathcart, who was relieved to see Ben Foster spare his blushes.
Then Oriol Romeu saw a shot blocked in a goalmouth scramble before Armstrong sent a curling effort over the bar all inside the first three minutes.
Watford responded with a tame free-kick into the wall from Cucho Hernández, leaving the hosts ruing their lack of set-piece specialist of the calibre of Ward-Prowse, three times a scorer against Foster in the past from that sort of range.
Josh King might have done better when he mistimed a shot from João Pedro’s cross, but it was a rare sight of goal for the Hornets, who were being swarmed by the Saints.
Walker-Peters crossed from the left invitingly for Armstrong, who could only head the ball over the bar from a very presentable opening, but the goal was coming and duly arrived in style, 20 minutes in.
Adams picked up a short pass from Armstrong surrounded by defenders on the 18-yard line, but succeeded in digging out an inch-perfect shot.
With little room for back lift, the striker just caressed the ball delicately into the top corner to open his Premier League account for the season.
Saints were dominating, but a brilliant piece of distribution from Foster suddenly launched a Watford counter-attack led by King, whose cross for Sarr looked set to lead to a goal until Walker-Peters got back just in time to clear Sarr’s shot, which struck the inside of the post and bounced along the line.
Undeterred by the narrow escape, the visitors kept pushing. Armstrong put one on a plate for Adams, but the Scot stooped to head the ball and got it all wrong, sending the chance down into the turf and up over the bar from six yards.
Saints’ front two were proving an almighty handful, but Adams’s sublime goal from the most difficult chance of the lot was all they had to show for it.
Armstrong sent a vicious curler whistling just past the post, before the impressive Walker-Peters darted down the left and cut the ball back, only for the former Blackburn striker blaze over on his left foot.
Unsurprisingly, Claudio Ranieri was unimpressed by what he’d seen, which was totally at odds from his team’s performance at Everton, where they scored five times.
Hernández and João Pedro were both sacrificed at the interval, with Tom Cleverley and Ken Sema introduced.
Juraj Kucka underlined the hosts’ newfound intent, trying his luck from 30 yards with a shot that veered away from goal, but a familiar pattern soon emerged.
Mohamed Elyounoussi nodded the ball down to Armstrong, who instinctively steered the ball towards the far corner with a clever half-volley that just drifted away from the target.
If Saints were not going to rue so many missed opportunities, they were going to need to keep an eye on Sarr, who remained a constant outlet for Ranieri’s side.
Mohammed Salisu dragged him down and Ward-Prowse tripped him up, both going into the book, as Sarr’s influence grew.
Still Saints were enjoying the better sights of goal, as Redmond and Armstrong both saw shots deflected wide, but still Watford remained alive in the contest.
Hasenhüttl’s first change was to bring on Stuart Armstrong for Elyounoussi with 20 minutes left, before Ward-Prowse was given a rest as Ibrahima Diallo was trusted with helping Saints see out the closing stages.
Saints seemed comfortable in the game until McCarthy was called upon to make a superb late save from substitute Ashley Fletcher, picked out by King’s pass, whose placed left-footed shot was destined for the bottom corner until the keeper’s big right hand intervened.
Hasenhüttl sensed Watford were gaining belief as four added minutes were signalled, and responded by beefing up his defence with the arrival of Lyanco from the bench, but his side were largely untroubled – as they had been for the bulk of the preceding 90 minutes.