Baku, November 10, AZERTAC Lionel Messi scored a hat-trick, including two sublime free-kicks, as champions Barcelona returned to winning ways against Celta Vigo in La Liga.Messi opened the scoring from the penalty spot after Junior Firpo's cross struck defender Joseph Aidoo's arm.Lucas Olaza equalised for the visitors with an excellent free-kick, but Messi put the hosts back in front with a similar attempt four minutes later.Messi stepped up again after half-time, before Sergio Busquets added a fourth.