Glasner felt they had their chances to deny the Gunners during the game.
He said afterwards: "In football sometimes it's crazy when I compare the performance in the first half to the Emirates. It was far better today but we were 3-1 down and there we had the lead so it's crazy because I thought we did many things well.
"The first box was a cross the second was a set-play and the third was a cross where we don't mark the man - we defended the box terrible. The quality of their players they punished us. If you want to beat a team like Arsenal everything has to be almost perfect. It was not good enough today. We created chances but the result is disappointing. In the box too many times we watched the players."
On their failure to take chances, he also said: "When you concede five it is unlikely you get a point! But yes, at 2-1 down we had a big chance and before they scored a third goal. We had big chances in the second half and then they scored the fourth and the game was over. We lost the belief to come back again. But we gifted them the goals and it's not easy to come back.
"From the first 60 minutes we can take a lot of positives. We have to defend the box but everything else one of our best performances. The pressure we gave them, the balls we were winning, in possession how we move the ball and how many chances we created. Of course, we will learn from it. We have to learn that when you give the top teams a crumb, they take the whole cake!"