Southampton coughed up an equaliser deep into stoppage time to draw 1-1 at Everton and hand West Brom another last-gasp lifeline in the fight against relegation.
Tom Davies scored with a deflected strike in the sixth of what was expected to be four added minutes to cancel out Nathan Redmond's 56th-minute header and sensationally preserve the Baggies' Premier League status.
It also served to deny the visitors from moving two points clear of danger, although they are above Tuesday's opponents Swansea City on goal difference.
Mark Hughes' men had looked to have taken a giant leap towards safety when substitute Redmond headed home Cedric Soares' cross 11 minutes after the restart.
But Maya Yoshida's second yellow card in the 85th minute opened the door to a period of rare late pressure from an Everton side that had been limp throughout and were booed off the pitch at both half-time and full-time.
That dissatisfaction came despite Davies' equaliser at the death, which deflected off Wesley Hoedt and left Hughes to remonstrate with official Jonathan Moss over the length of stoppage time.
Everton's performance up until the equaliser did nothing to dispel fan frustrations over their style of play, although Sam Allardyce was admittedly short on options in the attacking third as Wayne Rooney and Theo Walcott dropped out of the XI with knee and calf problems respectively, while Gylfi Sigurdsson and Dominic Calvert-Lewin were also unavailable.
The early evidence suggested they would have been spectators had they been on the pitch, with a sluggish first 15 minutes featuring little more than a midfield arm-wrestle for ineffective possession.
Charlie Austin eventually raised eyebrows around a muted Goodison Park, the striker's instinctive first-time effort from 20 yards drawing a smart diving save out of Jordan Pickford.
England international Pickford was next required to scoop away a deflected Oriol Romeu effort yet, despite his twin stops, Southampton could have few complaints about a laboured first 45 minutes finishing scoreless.
Both managers turned to their benches at the break as winger Redmond replaced the limping Mario Lemina, while Allardyce surprisingly called on Ramiro Funes Mori in place of Yannick Bolasie.
And it was the more proactive of the moves that was soon rewarded, Redmond ghosting in unmarked at the far post to head in Soares' delightful curling cross from the right.
1 - Nathan Redmond's goal was his first in the Premier League this season, with what was his 40th shot of the campaign. Fighting.— OptaJoe (@OptaJoe) May 5, 2018
The goal briefly appeared to encourage Everton into a rally as another substitute, Oumar Niasse, whipped an enticing delivery across the face of goal that failed to take a touch, before Yoshida's second yellow in the 85th minute heightened the tension.
Hughes' side had looked to have done enough despite that setback when Alex McCarthy spectacularly turned a goal-bound Leighton Baines free-kick over the bar.
But, just as West Brom appeared doomed to join the already relegated Stoke City in the Championship, they were brought back from the brink with Davies' intervention, the midfielder's effort from outside the box taking a wicked deflection off Hoedt and wrong-footing McCarthy.
Southampton must now pick themselves up for the crunch trip to Swansea, where three points could prove essential in view of a final-day visit from Manchester City.
Key Opta stats:
- Everton have lost just one of their 19 Premier League home games against Southampton (W13 D5).
- The side playing at home has only lost one of the last 18 league meetings between these sides (W11 D6), with Everton picking up a 3-0 victory at St Mary’s in August 2015.
- Southampton have now dropped 21 points from winning positions this season - only West Brom have lost more (26).
- The Toffees have lost their final home league game in just two of their last 14 seasons (W10 D2).
- Everton have conceded 55 Premier League goals this season - the last time they conceded more came during the 2003-04 campaign (57 goals conceded).
- The Saints have now conceded 14 goals from outside of the box this campaign - the most in the division.
- Nathan Redmond’s goal was his first in the Premier League this season with what was his 40th shot of this campaign.