Yannick Bolasie struck late for Crystal Palace to secure a draw in a match which Arsenal completely dominated.
Arsenal should have won comfortably to leapfrog Manchester City into third but instead they remain fourth in a nervy race for a Champions League spot.
Alexis Sanchez headed in Danny Welbeck’s chip to give the Gunners the lead but they lacked a killer instinct to put the result beyond doubt.
Bolasie then struck from distance, beating Petr Cech at his near post.
The Congolese forward’s equaliser alarmingly sucked the energy out of Arsenal and it was their London rivals who seemed more likely to score in the dying minutes.
Wilfried Zaha had the home defence backpedalling with a a surging run into the box, but luckily for the Gunners a heavy touch from the winger allowed Gabriel to nick the ball.
It was a performance which summed up Arsenal’s season. They missed a number of opportunities, had more than 70% of the possession but once again failed to secure three points in a match they were expected to win.
Meanwhile, Leonardo Ulloa’s stoppage-time penalty salvaged a point for 10-man Leicester as West Ham threatened to derail the Foxes’ Premier League title charge.
Jamie Vardy’s first-half strike gave the hosts the lead before he received a second yellow card in the 56th minute for a dive in the penalty area.
Andy Carroll equalised from the spot before Aaron Cresswell smashed home a brilliant second from outside the area.
But with seconds left Ulloa converted after Carroll had fouled Jeff Schlupp.
Earlier,an experimental Liverpool side won at Bournemouth to record a third consecutive victory in all competitions.
Roberto Firmino’s rebound and Daniel Sturridge’s header gave the visitors a commanding 2-0 lead at half-time.
Bournemouth rallied after the break but Joshua King’s stoppage-time strike came too late for a comeback.
The result lifts Liverpool up to seventh place in the Premier League table, while the Cherries remain 13th, reports the BBC.
Liverpool made 10 changes from Thursday’s momentous Europa League win over Borussia Dortmund as manager Jurgen Klopp named an inexperienced side.
The fringe players repaid the German’s faith with an accomplished performance which preserved their record of having never lost against Bournemouth.
Liverpool still have a slim hope of finishing in the top four but winning the Europa League is their likeliest route to Champions League qualification – and Klopp’s selection suggested he agrees.
Wales goalkeeper Danny Ward made his club debut and young defender Connor Randall was given a first Premier League start.
Jordon Ibe and his fellow winger, the less experienced Sheyi Ojo, shone as the Reds’ youngsters seized control of the first half.
However, it was two established first-team players who made the most telling contributions.
Top scorer Firmino opened the scoring from a rebound after Artur Boruc had saved Sturridge’s audacious backheel, before the England striker headed in Ibe’s free-kick just before half-time.
EPL RESULTS
Arsenal 1 – 1 Palace
Leicester 2 – 2 West Ham
Bournemouth 1 – 2 Liverpool
