"I was surprised because it looked as though their lad got a foot on the ball," said Ferguson.
"But Rob Styles turned us down four or five times last year so maybe it is payback time. But he still owes us another four."
Wayne Rooney's excellent finish 11 minutes from time doubled United's lead, the England striker's first goal of the season a perfect response to being left out of Ferguson's starting line-up.
"He made a difference when he came on," said Ferguson.
"If we are getting responses like that from players it is terrific for the club."