West Ham gifted a first half 2-goal lead with two own goals to share a point with Arsenal which dented their top 4 chase in the English Premier League matchday 29.
West Ham punished a sleepy Arsenal with Jesse Lingard, Jarrod Bowen and Tomas Soucek putting them in complete control and set to go level on points with fourth-placed Chelsea.
But when Alexander Lacazette's shot deflected in off Soucek in the 38th minute Arsenal came alive.
They laid siege to West Ham's goal for long periods of the second half and pulled back another goal as Craig Dawson scored into his own net just past the hour.
In a frenetic finale West Ham had chances to seal the points before Lacazette's 82nd-minute header earned Arsenal what had looked like an unlikely share of the spoils.
West Ham stay in fifth place with 49 points from 29 games, two below Chelsea. Arsenal moved up a place into ninth spot before Aston Villa's clash with Tottenham Hotspur later on Sunday.