Petr Cech was beaten at his near post on Sunday as Crystal Palace fought back from a goal down to draw 1-1 with Arsenal.
The keeper was unable to keep out an effort from Yannick Bolasie after Alexis Sanchez had given the hosts the lead late in the first half.
The draw all but ends Arsenal's title challenge and continues their poor run of form that has seen them win just two of their last seven league matches.
Asked whether Cech should have done better with the shot, Arsenal manager Arsene Wenger said: "I have to look at it again. It didn't look unstoppable but he will know that better than I do.
"Maybe we could have stopped the shot, but I will have to see it again."
The Gunners now look ahead to another home match against West Brom on Thursday evening, live on Sky Sports.
Watch the video above to see Bolasie's goal and the verdicts of Alan Smith and Thierry Henry.