Mile Jedinak's second-half penalty secured Crystal Palace a gutsy 1-0 victory at West Ham and guaranteed the Eagles' survival in the Barclays Premier League for another season.
If the league began when Tony Pulis took over in November, Palace would have started the game eighth in the table and this win meant they now sit 13 points clear of the relegation zone with three matches to play.
Only Chelsea have a meaner defence than Palace since the turn of the year and West Ham appeared increasingly bereft of attacking ideas in front of a home support that jeered all three of Sam Allardyce's substitutions and greeted the final whistle with a chorus of boos.
Allardyce made two changes to his starting line-up as Kevin Nolan returned from a hamstring injury to replace Antonio Nocerino in midfield and George McCartney came in for Guy Demel at the back.
Pulis started with a five-man midfield as Kagisho Dikgacoi was picked ahead of injured striker Marouane Chamakh.
Upton Park rose to its feet for a minute's applause before kick-off in memory of former West Ham forward Dylan Tombides who died of cancer aged 20 on Friday.
With the match under way, the hosts shaded an uneventful opening 10 minutes in which Andy Carroll enjoyed the best chance, heading over Nolan's cross after a sloppy clearance from Joe Ledley.
After a tentative opening, Palace gradually settled into the contest and almost broke the deadlock when Dikgacoi headed towards the net but Carroll was well-placed to clear off the line.
Palace were gathering momentum as Yannick Bolasie turned McCartney inside-out down the left before delivering a deep cross to Scott Dann who headed narrowly over under pressure.
The Eagles took the resulting corner quickly and Adrian Mariappa's driven shot was blocked by the diving Nolan, who was fortunate the ball narrowly avoided his arm.
In the 33rd minute, the home side were aggrieved not to be awarded a penalty, and with some justification, as Jedinak appeared to deliberately nudge Carroll over to prevent the forward reaching Matt Jarvis' cross.
West Ham finished the first half the stronger as Mohamed Diame's drilled shot from close range was stopped by Julian Speroni and seconds later the Palace goalkeeper did brilliantly to fend away Carroll's powerful header from six yards out.
The second period began brightly and Carroll should have done better when Stewart Downing's ball reached him at the back post but the striker hesitated before dragging his shot wide.
Palace could have been given a penalty when Jason Puncheon, who endured a quiet afternoon, was brought down by Pablo Armero but referee Martin Atkinson was unmoved.
Only three minutes later, the Hammers left-back was again at fault in the box as he clipped the legs of Cameron Jerome.
This time Armero was less fortunate as Atkinson pointed to the spot and Jedinak whipped the ball past Adrian to give Palace a 1-0 lead.
Pulis' side could have doubled their advantage in the 67th minute when some frantic defending twice presented Puncheon with chances in the box but the winger was unable to convert.
Bolasie's cross then just eluded Jerome as Palace began to dictate possession and enjoy the simmering atmosphere at Upton Park.
The home supporters mocked Allardyce when the West Ham boss replaced Jarvis with Carlton Cole in the 70th minute and some jeered Downing when he was brought off for Joe Cole soon after.
Joe Cole's introduction did at least produce some attacking spark for the Hammers as the former Liverpool midfielder first shot wide from the edge of the area before volleying over with four minutes to play.
But it wasn't to be for West Ham who will have to wait to secure their own status in the top flight next year with seven points now separating them from the relegation places.