Wayne Hennessey's howler cost Crystal Palace as they were beaten 1-0 at Aston Villa, Alan Pardew said.
The goalkeeper spilled Joleon Lescott's header over the line to give Villa their first home win of the Premier League season.
Pardew described Hennessey's error as unfortunate and noted his side made several mistakes.
"Wayne's mistake has cost us, but there were mistakes across the pitch, which aren't noticed. It's unfortunate, he's been great for us," said Pardew after seeing his side fail to score for the fourth successive league match.
"We came across an Aston Villa that worked very, very hard.
"I don't want to take anything away from them.
"They played well. I'm pleased for their manager."
Pardew noted his team have struggled with injuries, with Yannick Bolasie and Dwight Gayle among the Palace attackers ruled out.
"We're going to have to get back to the form that we showed previous to the injury to [Bolasie], we haven't really hit the ground since," said Pardew.
"[Bakary] Sako got 60 minutes, Connor [Wickham] got 45, that was probably the only plus for us."