Stoke-on-Trent - Arsene Wenger blasted Arsenal's defenders for their sloppy display as Stoke stunned the Gunners with a 1-0 victory on Saturday.
Wenger's side crashed to their first Premier League defeat of the season thanks to Jese Rodriguez's 47th minute strike at the bet365 Stadium.
Jese was allowed to gallop into the penalty area unchecked and Arsenal boss Wenger couldn't hide his disappointment.
"It was frustrating getting caught cold for the goal. Defensively there is no excuse. We gave them a cheap goal," Wenger fumed.
"We knew it was important not to make a defensive mistake. But we came out straight after half-time, were too sluggish and paid for it.
"We gave them too much freedom in the middle. I was not convinced by our central defence today."
Arsenal's careless defending wasn't the only frustration for Wenger, who felt Arsenal were wrongly denied an equaliser when Alexandre Lacazette's strike was ruled out for offside.
Replays showed the officials got the decision correct, but that didn't stop Wenger saying: "We were unlucky. I think we scored a regular goal that was given offside and it wasn't offside. It's a very easy decision.
"It's a difficult defeat to swallow. We had chances. We should have won the game comfortably."
After coming from behind to beat Leicester 4-3 in their season opener, this was a far less battling performance from Arsenal and Wenger admitted the loss was a big blow.
"It was difficult to get the fluency. We tried but we couldn't find the goal. There was lack of anticipation in the box with the second ball," he said.
"To lose a game like that is disappointing You don't want to lose games that you should win."