Arsenal boss Arsene Wenger has admitted that his side were not strong enough at the back in their 3-2 defeat to Stoke City on Saturday.
The Potters went ahead after 20 seconds when Peter Crouch netted from close range, while Bojan and Jonathan Walters added strikes later in the half to give Mark Hughes's men a 3-0 lead at the break.
The Gunners started a second-half comeback as Santi Cazorla netted from the spot while Aaron Ramsey added a second, but the home side held out for the three points at the Britannia Stadium.
Wenger told BBC Sport: "There's a lot of regret, we had given a lot. We showed great energy levels and a great response. The spirit of the team was fantastic. Defensively we missed start of game.
"We gave easy goals away. We were not decisive in challenges. Once we were 3-0 down, we had a mountain to climb. We did climb, but a bit unlucky I must say.
"What goes through the mind at half-time? Everybody is down so you have to pump the team up and make decisions to change what can be changed. It's frustrating to see them lose. There were a lot of positives - defensively we were not strong enough."
Arsenal are sixth in the Premier League following their fifth defeat in eighth visits to Stoke.
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