The crowd had lapped up hits, including 'Back To Black,' although there were jeers when Winehouse dedicated 'Wake Up Alone' to husband Blake Fielder-Civil, in jail awaiting sentencing for GBH and perverting the course of justice.
The singer could not resist pining for her imprisoned husband and punched a crowd member hard in face. Festival boss Michael Eavis said of the singer's punch: "The man deserved it. He grabbed Amy's breasts as she went past."
Winehouse spokesman said: "One person misbehaving did nothing to spoil a great couple of days."However, another crowd member in the front row, said it was a girl who was hit, after trying to give the singer a high-five. Avon and Somerset Police received no complaints and said that there would be no investigation.