Nottingham Forest came out on top in a seven-goal thriller at the City Ground to climb out of the bottom three and leave Southampton on the brink of relegation.
In a raucous atmosphere on a rain-soaked night, Forest established a two-goal cushion on three occasions - and each time the visitors responded to pull themselves back into the contest.
But Southampton couldn't manage an equaliser. Now they must win all three remaining games and hope either Forest don't pick up another point, or Everton fail to get more than one, otherwise they will be back in the Championship for the first time since 2012.
In contrast, Forest have their fate in their own hands.
Taiwo Awoniyi scored his first brace for the club in the space of three first-half minutes, profiting first from Danilo's superb crossfield pass that allowed Brennan Johnson to set him up to volley home from close range after a goalmouth scramble.
Carlos Alcaraz pulled one back for Southampton, only for Morgan Gibbs-White restore the home side's two-goal cushion from the penalty spot a minute before the break.
After Lyanco's header had given Southampton fresh hope at 3-2, Gibbs-White was then instrumental in Forest's fourth.
The England Under-21 international had the awareness to flick Johnson's cross into an unmarked Danilo's path for a cool finish, rather than go for goal himself.
James Ward-Prowse's injury-time penalty ensured nerves were being shredded right to the very last seconds of a staggering day of Premier League action.
At kick-off, both these sides occupied the bottom two places and ended with Forest scrambling up to 16th - three points clear of third-bottom Leicester - and with rising hopes of preserving their top-flight status.
Southampton's slide towards the Championship
Southampton remain eight points from safety with three games remaining in the Premier LeagueThis is Southampton's 11th consecutive Premier League season, along with West Ham. Only the 'big six' and Everton have been in longer, which is why they were given 'long-term shareholder' status in Project Big Picture.
This was the plan to reshape English football, formulated by the biggest clubs in the autumn of 2020, but disappeared amid the European Super League row that followed.
Saints were never actually told of the plan before it was launched but, at the time, they did appear to be one of those clubs who could survive quite easily - even if the days of Mauricio Pochettino and Ronald Koeman, which saw the club into Europe, had disappeared.
But ownership issues and poor recruitment have dragged them down and, this season, they have made a complete mess on the management side.
Ralph Hasenhuttl's dismissal just before the World Cup came after a run of one win in nine games. His replacement, Nathan Jones, lasted only 95 days before he was sacked and Ruben Selles was given the job until the end of the season.
However, after winning two of his first three matches in charge, Selles has not presided over another victory.
Their only point in the last seven games came at Arsenal on 21 April, when Southampton held a two-goal advantage entering the final five minutes.
They have not kept a clean sheet since 12 March and the manner in which Forest got their goals in such a crucial game was symptomatic of a team who are just not good enough.
Forest's second came when Alcaraz gifted possession to the hosts 30 yards from his own goal.
The third was when Ainsley Maitland-Niles slipped inside his own box and rather than temper what he was going to do, tried to execute a clearance anyway and only succeeded in kicking Johnson on the back of his leg.
Given they had trailed by two goals at half-time in 32 Premier League games and lost the lot since 2016, hopes were not high of a comeback.
That they came so close was to their credit.
Had it not been for a couple of brave Keylor Navas punches under pressure when Southampton were only one down, or that a Forest player managed to get on the end of a corner in the 101st-minute of a contest extended by two long Video Assistant Referee (VAR) checks near the end, they might have got a draw.
Instead it was another loss and, nearly, the end of their time as a top-flight club.
Forest fans are their 12th man
Forest couldn't have chosen a better time to complete successive home wins for the first time this season.
Their last 12 points have all come at the City Ground and 15 out of 16 since their only away win, at Southampton, in January.
The importance of the fans to their club's season cannot be understated. Manager Steve Cooper mentions it in nearly every lot of programme notes. While not particularly intimidating for the opposition, it is manic in favour of the hosts.
At the final whistle the noise was intense. The Queen anthem 'Don't Stop Me Now' was greeted with scarf-twirling electricity after Cooper and his players had been given a jubilant send-off.
Of course, it takes more than an atmosphere to keep a team up and there is plenty of jeopardy in the games that follow against Chelsea, Arsenal and Crystal Palace.
Gibbs-White, though, is starting to show why Forest spent £42.5m on him with consistently good performances.
And while Awoniyi's six goals is hardly evidence of a free-scoring frontman, the confidence gained from his first-half efforts bodes well for the next few weeks and can only help Forest in the battles ahead.
Line-ups
Nottm Forest
Formation 4-3-3
12Navas
24Aurier38Felipe19Niakhaté32Lodi
22Yates5Mangala28Danilo
20Johnson9Awoniyi10Gibbs-White
12Navas24AurierSubstituted forWorrallat 64'minutes38Felipe19Niakhaté32LodiBooked at 78minsSubstituted forToffoloat 81'minutes22YatesSubstituted forKouyatéat 70'minutes5Mangala28Danilo20JohnsonSubstituted forBolyat 81'minutes9AwoniyiSubstituted forSurridgeat 81'minutes10Gibbs-WhiteSubstitutes
4Worrall11Lingard13Hennessey15Toffolo16Surridge21Kouyaté23Freuler30Boly34A AyewSouthampton
Formation 4-2-3-1
1McCarthy
2Walker-Peters35Bednarek37Bella-Kotchap3Maitland-Niles
8Ward-Prowse45Lavia
32Walcott26Alcaraz17S Armstrong
10Adams
1McCarthy2Walker-Peters35Bednarek37Bella-KotchapSubstituted forLyancoat 38'minutes3Maitland-Niles8Ward-Prowse45Lavia32WalcottSubstituted forSulemanaat 61'minutes26AlcarazSubstituted forA Armstrongat 76'minutes17S ArmstrongSubstituted forEdozieat 76'minutes10AdamsSubstituted forOnuachuat 76'minutesSubstitutes
4Lyanco6Caleta-Car9A Armstrong12Onuachu18Mara20Sulemana23Edozie24Elyounoussi31BazunuReferee:Michael OliverAttendance:29,154Live Text
Match ends, Nottingham Forest 4, Southampton 3.
Second Half ends, Nottingham Forest 4, Southampton 3.
Corner, Southampton. Conceded by Moussa Niakhaté.
Attempt blocked. Paul Onuachu (Southampton) left footed shot from the centre of the box is blocked. Assisted by Lyanco.
Foul by Paul Onuachu (Southampton).
Cheikhou Kouyaté (Nottingham Forest) wins a free kick in the defensive half.
Goal! Nottingham Forest 4, Southampton 3. James Ward-Prowse (Southampton) converts the penalty with a right footed shot to the centre of the goal.
Penalty Southampton. Roméo Lavia draws a foul in the penalty area.
Penalty conceded by Sam Surridge (Nottingham Forest) after a foul in the penalty area.
Attempt saved. James Ward-Prowse (Southampton) header from the left side of the box is saved in the centre of the goal. Assisted by Ainsley Maitland-Niles.
Corner, Southampton. Conceded by Moussa Niakhaté.
Kamaldeen Sulemana (Southampton) wins a free kick on the right wing.
Foul by Harry Toffolo (Nottingham Forest).
Delay over. They are ready to continue.
VAR Decision: No Goal Nottingham Forest 4-2 Southampton.
GOAL OVERTURNED BY VAR: Felipe (Nottingham Forest) scores but the goal is ruled out after a VAR review.
Offside, Nottingham Forest. Morgan Gibbs-White tries a through ball, but Felipe is caught offside.
Foul by Lyanco (Southampton).
Morgan Gibbs-White (Nottingham Forest) wins a free kick in the attacking half.
Kyle Walker-Peters (Southampton) wins a free kick in the defensive half.
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