Said Benrahma cancelled out Danny Welbeck's strike to salvage a point for West Ham United as their hopes of finishing in the top four suffered a major setback at Brighton & Hove Albion.
West Ham looked the likelier scorers in the first half as two Pablo Fornals strikes were blocked and Tomas Soucek worked Robert Sanchez in the Brighton goal.
At the other end Alireza Jahanbakhsh was denied by the legs of Lukasz Fabianski and when he did beat the West Ham goalkeeper on 55 minutes his angled attempt went wide.
With six minutes remaining Welbeck latched on to Percy Tau's through-ball and dinked the ball over the advancing Fabianski to break the deadlock with his 50th Premier League goal.
Substitute Benrahma responded with a curling strike in off the post on 87 minutes, but the visitors could not produce a crucial winner.
David Moyes' team lie sixth with 59 points, five fewer than fourth-placed Chelsea with two matches to play, and one fewer than Liverpool, who have a match in hand.
Brighton, who have never lost a Premier League match against West Ham, are 17th with 38 points and their top-flight status secured for another season.
Brighton: 18 May v Man City (H)
West Ham: 19 May v West Brom (A)
Referee: Andre Marriner. Assistants: Scott Ledger, Simon Long. Fourth official: Simon Hooper. VAR: Paul Tierney. Assistant VAR: Andy Halliday.