Alexandre Lacazette scored deep into injury time to deny club legend Patrick Vieira a winning return to Arsenal as Crystal Palace manager.
Lacazette pounced after Palace failed to clear a corner and Gabriel Martinelli's effort was saved.
The Gunners took the lead through Pierre-Emerick Aubameyang but Christian Benteke continued his good record against the Gunners with the equaliser.
Odsonne Edouard hammered in Palace's second but they could not hang on.
