Two first-half goals condemned Southampton to defeat at Turf Moor, as Burnley gave their survival hopes a shot in the arm with three vital points in the Premier League.
Saints started brightly, only to fall behind to Connor Roberts’s bolt from the blue – a sweet curling shot from 20 yards that left Fraser Forster no chance.
The goalkeeper was in inspired form between the sticks as Burnley took the initiative, but at the other end Oriol Romeu squandered two presentable headed chances from James Ward-Prowse corners.
Having failed to extend their lead, the hosts finally got the killer second rather too easily just before the interval, as Neil Collins headed in from a corner.
Saints responded with a second-half flurry shortly after Burnley had seen a third goal disallowed for offside, but Nick Pope denied Ché Adams and Ward-Prowse as the Clarets moved to within a point of safety with victory.
Ralph Hasenhüttl named an unchanged side after a resolute Saints display ended a six-match winless run with a gutsy 1-0 victory over Arsenal on Saturday.
The only alteration on the bench saw Ibrahima Diallo return to the squad in place of Jack Stephens, as Saints continued in the 5-4-1 formation that served them well last time out.
Burnley’s precarious league position, compounded by a stoppage-time equaliser for Everton against Leicester 24 hours earlier, contributed to a nervous start from the home team, playing at Turf Moor for the first time since the departure of Sean Dyche after nine and a half years at the helm.
Saints had a golden chance to take the lead when Ward-Prowse’s early corner was met by the unmarked Romeu, whose powerful header whistled inches wide with Pope rooted to the spot.
It was a reprieve the Clarets took full advantage of as Roberts curled in a stunning opener on 12 minutes.
Receiving possession near the right corner of the penalty area, the Welshman took a touch inside and let fly on his weaker left foot with a curling shot that even Forster, in inspired form against Arsenal, could not reach.
Forster was called upon to make two saves in the next five minutes to keep Saints in contention as the momentum of the game swung dramatically in Burnley’s favour.
First Wout Weghorst left Lyanco on the floor as he turned away from him in the box, but in delaying the shot the angle narrowed sufficiently to allow Forster to make a sprawling stop.
Then Jay Rodriguez tested his former teammate with a snapshot after Weghorst’s knockdown deflected kindly into his path, as the hosts rode a tidal wave of confidence having edged in front.
Forster was kept busy from a corner soon after, again thwarting Rodriguez, whose downward header was destined for the far corner before the keeper intervened with a big left hand.
When the danger was not properly cleared, Weghorst missed a gilt-edged chance when he headed against the outside of the post from six yards.
But it was from another corner at the other end that Burnley should have been punished for their profligacy.
Again Romeu was left alone to wander towards the six-yard line to meet another teasing Ward-Prowse delivery, only to this time head wide of the opposite post as Burnley got away with another narrow escape.
From open play, however, the momentum remained with the hosts. Roberts teed up Dwight McNeil, whose skidding drive from 20 yards forced another sharp low save from Forster, who was again at the top of his game.
But Saints’ last line of defence was powerless to prevent Burnley grabbing a timely second just before the interval.
Josh Brownhill, whose pass found Roberts for the opener, helped himself to a second assist when his left-wing corner was nodded in by Collins.
Turf Moor held its breath when VAR scrutinised whether there had been a touch from the offside Jack Cork on its way into the net, but the goal stood.
Saints needed to improve, and fast, but began the second period in identical fashion as James Tarkowski was afforded a free header from another Brownhill corner, only to send his header over the crossbar.
Having started the game well, there was still little sign of Saints rediscovering that form, and only a VAR decision prevented a three-goal deficit just after the hour.
When Tarkowski headed the ball back across goal, Forster parried and was clattered for his troubles, as former Saints Rodriguez and Cork charged in to bundle the ball into the unguarded net.
Fortunately, on closer inspection Rodriguez’s initial touch did come off Cork on its way in, and the midfielder was certainly offside, offering Saints a lifeline.
Hasenhüttl responded with an instant double change, introducing Nathan Redmond and Ché Adams for Stuart Armstrong and Mohamed Elyounoussi.
The substitutes immediately combined to good effect, as Redmond’s cross was struck firmly on the volley by Adams, whose contact was true but too close to Pope, who made an impressive reaction save.
Suddenly Saints had found some impetus. Ward-Prowse sized up a free-kick in shooting range, albeit not on his favourite side, that forced Pope to tip the ball over for a corner.
From the resulting delivery, Adams was in the right place again when the loose ball landed at his feet, but Charlie Taylor lunged in to make a crucial block.
It was a flurry in which Saints had to capitalise to set up a grandstand finish, as subsequently the game rather drifted away from Hasenhüttl’s side, who were left to regret an off-colour first-half display.