"Porter was the difference," said Gray. "His finishing was first-class and was something we just couldn't find.
"We had plenty of possession, but we didn't use it to put pressure on them. We didn't work their goalkeeper hard enough and although Porter took the chances well, we gifted them with both goals with some poor defending.
"Possession-wise we dominated the game after getting off to a sloppy start. Even when we went 2-0 down, we started to go forward and put them under pressure at the back. But over the 90 minutes we didn't do enough up front to get anything out of the game."
Northampton's best chances fell to Adebayo Akinfenwa, his first going inches over the bar late in the first half and the second flashing across the face of goal midway through the second half. However, the visitors were always second best, thanks to Porter's finishing.