Substitute Quincy Owusu-Abeyie scored the only goal two minutes from full time to help Ghana claim victory over Latvia in their final warm-up match ahead of the World Cup.
Ghana, who were thumped 4-1 by Holland in their only other pre-finals friendly, dominated for large parts of the game, which was being played at the Stadium MK in Milton Keynes.
Coach Milovan Rajevac made eight changes to the team that lost to the Dutch, including handing a full debut to Portsmouth midfielder Kevin-Prince Boateng.