Matheus Franca's stoppage-time goal for Crystal Palace denied Southampton just a third Premier League win this season and put them on the brink of an unwanted record.
Franchi's late substitute strike to secure a 1-1 draw means Saints face relegation at the weekend if they lose to Tottenham and Wolves beat Ipswich.
If relegation is confirmed on Sunday, Southampton will become the first team to leave the league despite still having seven games to play.
Even the 2007-08 Derby team, considered the low bar by which all weak Premier League teams are judged, had six games left, as did Huddersfield in 2019 and Sheffield United four seasons ago.
Saints have at least reached double figures for the season but are still one point short of Derby's record low total of 11.
Palace arrived at St Mary's on a five-game winning run and buoyed by reaching the FA Cup semi-finals at the weekend, a form that has earned manager Oliver Glasner a move to Bundesliga side RB Leipzig.
Looking to secure a seventh win in a row, they almost scored in the 90th second when Jean-Philippe Mateta, still sporting a badly bandaged ear following a horrific injury suffered against Millwall last month, fired a 25-yard shot off the underside of the crossbar.
Palace had not conceded an away goal since Christmas so it came as a surprise when Saints took the lead after 20 minutes.
Matheus Fernandes exchanged passes with Flynn Downs on the right before crossing for 6ft 7in (190cm) striker Onuachu, who headed home.
“We're not sleeping,” chanted the home fans. “Say hello to Millwall,” replied Palace from the flank.
Mateta looked certain to level the scores in the 35th minute, cutting into the penalty area and firing a low shot towards goal, but Aaron Ramsdale saved with one hand.
Ismaila Sarr broke forward after the break and passed to Eberechi Eze, but the England striker's corner kick went into the side netting.
Eze took the free-kick after Downs brought him down and then Ramsdale saved Eddie Nketiah's shot and the ball rebounded off the striker and went wide of the goal.
There were groans as the fourth official indicated four minutes of added time and moments later Palace equalised.
You could almost hear the cheers from Derby as Jefferson Lerma's cross was headed in by Franca between Ramsdale and the near post.
Palace almost scored the winner, which would have been even crueler to the Saints, but Nketiah's shot flew just over the crossbar.
Sourse: breakingnews.ie
