Arsenal manager Arsene Wenger bemoaned defensive mistakes after his side's defeat against Southampton on Thursday.
Goalkeeper Wojciech Szczesny endured a night of misery with two terrible mistakes, one in each half, and the Frenchman says the defeat will be "difficult to swallow" as the Saints open up a three point gap in the race for a top-four finish.
"We looked like we were in control until the first goal," Wenger said.
"Overall they defended better than us. We made two mistakes and that cost us. The keeper kept them in the game with early chances and after that we helped them a lot.
"The team really had a great generous attitude after what we had given at West Ham and to lose a game like that is difficult to swallow. Southampton are a good side but beatable today and we can only look at ourselves.
"When you're 1-0 down in the Premier League everyone tends to defend well and they did."
With the Saints leading 2-0, referee Craig Pawson opted to only show a yellow card to Florin Gardos in what looked to be a last-man challenge on Alexis Sanchez.
And Wenger says the referee made a mistake in letting the Romanian stay on the pitch.
"We had chances today and were a bit unlucky as when [Alexis] Sanchez was through at 2-0 I don't see how the referee can't give a red card. It looks like he didn't get it right," said the Frenchman.
"We have to learn to win these kind of games. We will give our best to be as high as we can. We have to be more consistent."
