Yoann Arquin scored with a penalty and Nathan Elder pulled another one back near the end but Southend ran out 3-2 winners in Saturday's League Two clash at Edgar Street thanks to goals from Neil Harris, Elliot Benyon and Ryan Hall.
"I don't think we got started until the last 10 minutes of the game." said O'Kelly.
"We stepped up a gear, I know it helps when you get a goal, but I was over the moon to get the penalty because it got us back in the game.
"We kept fighting to get back into the game and we could have got something out of it at the end."
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