Boss Cotterill said afterwards: "I told the players that if they made a mistake and Kris Commons was on the end of it he would punish us and that's just what happened.
"I know the lad from my days at Stoke and he's got ability. I knew what he was capable of doing.
"Overall I thought we were the better side and we had the better chances but we didn't take them and then made too many mistakes at the other end."