City looked likely to earn themselves a point until seven minutes from time as Ian Henderson converted a spot kick before the visitors were handed another in injury-time to seal all three points.
Hopkin said following the result: “It’s what you do in both boxes.
“Most managers will tell you that what goes on between each box is irrelevant. It’s how you get there and how you’re going to do it.
“I don’t think there was much in the game for 80 odd minutes. Both sides were cancelling each other out.
“We then conceded a very soft penalty. You can’t let players pick the ball up and run 10 yards at your three centre halves.
“Before you know it, you give the referee an opportunity. Then the second one was just one of those when you’re chasing the game and you give the ball away.
“But sometimes you’ve got to do better with the chances.
“We’ve been one-on-one (with the keeper), we’ve had a free header, we’ve had shots at goal. If you’re not taking them and you’re giving away penalties at the other end, you’re not going to get the result.”