Crystal Palace 3, Arsenal 0
Arsenal manager Arsene Wenger refused to discuss his future after the Gunners plunged deeper into crisis with a crushing defeat at resurgent Crystal Palace.
Goals from Andros Townsend, Yohan Cabaye and Luka Milivojevic boosted Palace's Premier League survival prospects with a first win over the north Londoners for 23 years.
It was a seventh loss in 12 games for Arsenal, a fourth consecutive league away defeat and the fifth time in nine fixtures that they have conceded three or more goals.
They look increasingly likely to miss out on Champions League qualification for the first time since Wenger's first season, 20 years ago, but he rebuffed questions about his position.
"Look, honestly I'm disappointed tonight after such a long time to see that we lose a game the way we lost it," said the Frenchman, whose team are sixth, seven points off the top four.
"At the moment and especially tonight I think it would be inconvenient to speak about me. It's more painful to lose a game the way we lost it."
Palace remain 16th but climbed six points clear of the relegation zone, leaving manager Sam Allardyce to savour his finest week since taking charge in December.
"I just looked at the stats for the second half and I don't think Arsenal had one shot on target," he said.
"Our defensive solidarity gives us the platform to win matches. Our attacking players are enjoying themselves more than ever this season.
"We have got everything right at the moment right and we just have to keep it up for a little bit longer. One or two more results and we should be safe. It's a massive night for everybody and a massive week for us all."
Palace had last beaten Arsenal in October 1994, with two goals from John Salako, but they were superior here from the start and led on 18 minutes when Townsend tucked in Wilfred Zaha's low cross from the right.
The Gunners struggled to land a blow, although Alexis Sanchez curled narrowly wide and on-loan defender Mamadou Sakho enhanced his burgeoning hero status with blocks to deny Mesut Ozil and Sanchez before half-time.
Zaha terrorised Nacho Monreal and he provided Palace's second on 63 minutes, slipping as he crossed in almost identical fashion to the first goal for Cabaye to float a shot shot over Emiliano Martinez and into the far corner.
The hosts added a third six minutes later when January signing Luka Milivojevic drilled his first goal for the club from the penalty spot after Martinez had been penalised for a trip on the tireless Townsend.