Goals from Mason Greenwood, Archie Brown and Vedat Muriqi secured victory for the Turkish side against the Premier League club.
Alexander Isak and Trey Nyoni scored for Liverpool, but their efforts were not enough to prevent defeat.
Speaking at his post-match press conference, Iraola identified Liverpool’s poor defending from set-pieces as the major reason for the loss.
“The main reason I can find myself losing the game is we conceded [from] three set pieces,” Iraola said.
“It’s something that we were doing very well in the league. I think we were dealing [with it] quite well until today.”
