Benitez blamed his men’s mistake after losing his first game since he signed for the Merseyside-based club.
After a tepid first half performance from both side, it was the hosts who broke the deadlock through full-back Matty Cash on 66 minutes.
Dean Smith’s men doubled their advantage three minutes later when Lucas Digne scored an own goal before Leon Bailey settled the hosts’ victory 15 minutes before the final whistle.
Speaking to the media after the game, the former Liverpool and Chelsea boss reacted to the Toffees’ first defeat of the season.
"I think that we started the game quite well, we had a lot of situations on the counter in the first half and the final decision was not right,” Benitez told BBC MOTD.
“We had a couple of chances in the second half then conceded and again soon after. We started with too many problems but the team was fighting well.
"Sometimes if you have players you can make situations and have fresh legs. In some positions we were short of legs.
"Salomon Rondon, Demarai Gray, Alex Iwobi, we had some situations where it could have been different.
"We made mistakes too soon, too early, too close and it was difficult to react. Hopefully we can manage that in the future."
