Winehouse was spotted scuffling with an unseen fan towards the end of her hour-long set on the Pyramid Stage on Saturday night. She climbed down into the pit to interact with supporters while performing her hit song 'Rehab' shortly before the incident took place.
James Gostelow, 25, said that the singer elbowed him after another crowd member threw a hat at her. It is believed that she may then have been angered further over a comment made by another reveller, causing her to continue lashing out at the audience.
"I saw a hat being thrown from behind me and it hit Amy's beehive. She looked down, saw me looking up, and her elbow went for me," Gostelow told the BBC. "She caught my forehead, then someone may have shouted something from the back, which is when she went in again."
He added that he feels "disappointed" over the incident but does not think it is necessary to involve police.
"At the end of the day it is all part of being at the front and being pushed by thousands of people. It is all part of the Glastonbury experience," Gostelow explained. "I'm just pleased I got to see her. She did a great act.
"Not everyone can say they have been hit by Amy Winehouse. I just want to shake the person who threw the hat."
Police had previously stated that they would not investigate the matter unless a complaint of assault was received.