Southampton’s Premier League status is hanging by a thread after a 4-3 defeat in a gripping relegation six-pointer at the City Ground.
Hosts Nottingham Forest raced into a two-goal lead inside 21 minutes despite Saints starting on the front foot in the East Midlands, as Taiwo Awoniyi fired a first-half brace.
But the home nerves never really went away, as Carlos Alcaraz quickly pulled one back at the end of a swift counter-attack.
Saints continued to push and probe all night, but Forest often broke with purpose, and the visitors shot themselves in the foot when Ainsley Maitland-Niles needlessly conceded a penalty shortly before half time, converted by Morgan Gibbs-White.
Substitute Lyanco reduced the deficit once more early in the second period, prompting constant Saints pressure, but another counter sealed it for the hosts, as Gibbs-White brilliantly set up Danilo to finish the job.
James Ward-Prowse did give Saints faint hope of a stoppage-time revival with a spot-kick of his own deep into stoppage time, but Forest were able to see out the remaining seconds for a victory that propels them three points clear of the drop zone with three games to play, leaving Saints eight from safety.
Rubén Sellés made three changes to his side following the 3-1 defeat at Newcastle last time out in which Saints were unable to convert a half-time lead into victory.
There were recalls for Maitland-Niles, Theo Walcott and Ché Adams, as Lyanco, Moussa Djenepo and Kamaldeen Sulemana dropped to the bench.
Straight away there was a purpose about Saints. Adams challenged Keylor Navas under a high ball, forcing the vastly experienced goalkeeper into a nervous punch.
Then Adams tried his luck from 20 yards with a curling shot that sailed over, before an even better chance for the striker inside the first six minutes.
Winning the ball high up the pitch through Alcaraz, Walcott was able to find Adams in space in the box. As he turned inside on to his right foot, Felipe was able to slide in and make a crucial last-ditch block to deflect Adams’s shot off target when Navas looked beaten.
Fast starts have been a recurring theme in recent Saints matches and this was no different.
Forest responded with a first counter-attack, led by Gibbs-White, whose pass to his right found Brennan Johnson in a promising position, but the Welshman dragged a low shot wide of the far post – fortunately for Saints not wide enough to reach the onrushing Awoniyi, who was sliding in.
The game was still only 12 minutes old when Ward-Prowse delivered his third corner of the night, this time flicked on by Walcott at the near post, but nobody in a blue shirt read the script when a simple tap-in would have been up for grabs at the far.
Saints could be encouraged by their start but it was Forest who struck first with a vital opening goal against the run of play.
It was one long ball that exposed the visitors, as Danilo arrowed a raking pass over the head of Maitland-Niles for the speedy Johnson, and suddenly Saints were in trouble, as Johnson’s first-time pass across goal was ruthlessly dispatched by Awoniyi.
Sellés’s side must have still been coming to terms with that setback when Awoiyi struck again, leaving Saints staring relegation in the face 20 minutes into the game.
Alcaraz had just threatened to equalise from the edge of the box before he conceded possession to Serge Aurier deep inside his own half.
Twice Saints failed to clear from the resulting cross and Forest kept the ball alive, as Danilo helped it on and Awoniyi slammed it in, pinning Armel Bella-Kotchap and swivelling to volley home emphatically past the helpless Alex McCarthy.
One bright spark of Saints’ first half had been Stuart Armstrong, who threatened to halve the deficit only to be met by the flying figure of Aurier, who blocked his shot.
But Saints threw themselves a lifeline when Ward-Prowse won possession to start an excellent counter-attack.
In similar fashion to the goal at Newcastle last week, this time Adams carried the ball into Forest territory and found Armstrong to his left, who brilliantly disguised his pass across the box into the path of Alcaraz, who netted his fourth goal since arriving from Argentina in January.
Back came Forest, intent on restoring their two-goal lead immediately. Ryan Yates was thwarted by McCarthy, before Johnson left Bella-Kotchap in his wake from another electrifying break.
With Awoniyi hat-trick hunting to his left, Johnson was denied an assist by a brilliant last-ditch intervention by the sliding Jan Bednarek.
The Pole may have limited the damage, but Bella-Kotchap was unable to continue having pulled up with what looked like a hamstring injury in attempting to chase the lightning-quick Johnson.
Just as Saints had a foothold in the contest, Forest extended their lead from the penalty spot a minute before the interval.
It was certainly avoidable, too, but Maitland-Niles just hesitated momentarily before clearing his lines, and Johnson was sharp enough to nip in front of the defender, who, instead of booting the ball, booted Johnson in the boot, and referee Michael Oliver had no option.
Up stepped Gibbs-White, whose spot-kick lacked conviction but did enough to beat McCarthy, who dived to his left, as the ball clipped his trailing leg on its way into the middle of the net.
If Saints were to find a way back – not just into the game but into the survival fight – they needed to find something early in the second half.
Enter Lyanco, on for Bella-Kotchap in the 38th minute, who rose to head home a Ward-Prowse corner six minutes after the interval – his first Saints goal on his 45th appearance in English football.
Another Ward-Prowse set-piece moments later caused more problems for a nervy home defence, who had looked suspect all night.
Again the ball fell to Lyanco, who instinctively tried to play it back across goal rather than picking out the unmarked Adams on the edge of the six-yard box.
Saints were, rightly, playing like their Premier League lives depended on it. Kamaldeen was introduced for Walcott on the hour as Sellés searched for a way to turn his team’s dominance into chances.
An explosive burst from the Ghanaian took him to the byline, winning a corner from which Forest panicked again, as Lyanco met another Ward-Prowse delivery, but Navas punched away just in front of the poaching Adams.
Saints had been camped in Forest territory since half time, but the hosts had carried a counter-attacking threat all night, and another devastating break took the game away from Saints once and for all.
With 17 minutes remaining, Johnson escaped down the right and Gibbs-White brilliantly backheeled his low cross into the path of Danilo, who finished the job to take Forest out of the bottom three and leave Saints eight points adrift of safety with three games to play.
Paul Onuachu, Adam Armstrong and Samuel Edozie all arrived off the bench in an attempt to rescue a result, but Saints had left themselves far too much to do.
Another twist arrived in the shape of a last-gasp foul on Roméo Lavia, inviting Ward-Prowse to repeat Gibbs-White’s trick of burying the penalty straight down the middle, but Forest were able to hang on and celebrate a victory of enormous importance in their own quest to beat the drop.
Nottingham Forest: Keylor Navas, Felipe, Moussa Niakhaté, Renan Lodi (Harry Toffolo 81), Sérge Aurier (Joe Worrall 64), Orel Mangala, Ryan Yates (c) (Cheikhou Kouyaté 70), Danilo, Taiwo Awoniyi (Sam Surridge 81), Morgan Gibbs-White, Brennan Johnson (Willy Boly 81).
Unused subs: Wayne Hennessey, Jesse Lingard, André Ayew, Remo Freuler.
Goals: Awoniyi (2), Gibbs-White, Danilo.
Southampton: Alex McCarthy, Ainsley Maitland-Niles, Jan Bednarek, Armel Bella-Kotchap (Lyanco 38), Kyle Walker-Peters, Theo Walcott (Kamaldeen Sulemana 61), Carlos Alcaraz (Adam Armstrong 76), Stuart Armstrong (Samuel Edozie 76), Roméo Lavia, James Ward-Prowse (c), Ché Adams (Paul Onuachu 76).
Unused subs: Gavin Bazunu, Duje Ćaleta-Car, Mohamed Elyounoussi, Sékou Mara.
Goals: Alcaraz, Lyanco, Ward-Prowse.