Rafa Benitez says Newcastle United's fans were "fantastic" at Selhurst Park – apart from one.
A beer bottle was thrown from the away end at Crystal Palace's Aaron Wan-Bissaka during yesterday's goalless draw.
The bottle struck the defender, who was uninjured.
Benitez's players were backed by 2,900 fans at the game, which was also watched by United owner Mike Ashley.
Supporters chanted for Ashley to "get out of our club" and also raised a banner advertising a website which promotes rival retailers to the billionaire's Sports Direct chain.
Asked about the bottle incident, Benitez said: "We had almost 3,000 fans here and one made a mistake – but the rest were fantastic.
"If we want to be stronger, we need the fans behind us. Our fans away have been outstanding, no doubt about that."
Palace manager Roy Hodgson said: "Didn't see it. My focus tends to be on the football. I obviously can't comment from it."
The incident is likely to be investigated by the football authorities in conjunction with the police.
Alcohol is not allowed within sight of the pitch in football stadiums by law.
Newcastle defender Fabricio Coloccini was struck by a coin thrown from the home end at Selhurst Park in February 2015. However, no action was taken against Palace or the individual.