Over the last 12 months, Fletcher's reputation has soared.
Ferguson is obviously well aware of his fellow countryman's abilities at shutting down the opposition.
But the United manager admitted Fletcher's volley took him by surprise.
"Darren is an improving player," said Ferguson.
"Each year we have seen his performance level go up and up and it is still doing so.
"But I have to admit I did not expect that goal. It was really well taken."