Hughes, who was to pitch a Triple-A game Saturday as he recovered from a back injury, had his outing ended when he gave up a double to Hunter in the pivotal inning.
Purchase should compete alongside Marc Hunter in the lightweight double sculls, continuing the partnership from the 2008 Olympics, while Reed has spent the 2010 World Cup season in the pairs with Andy Hodge.
The Giants' Hunter Pence scored on a double-play groundout by Brandon Crawford to give the Giants a 1-0 lead in the bottom of the seventh and Pence hit a sacrifice fly in the bottom of the eighth to make it 2-0.
The former King's School, Worcester pupil teamed up with Mark Hunter to win gold in the men's lightweight double sculls in Beijing - the first time Great Britain had won the Olympic title in this category.
However, home plate umpire Hunter Wendelstedt called the pitch a ball and Berkman went on to hit a double that would score Jorge Posada from first base and give the Yankees a 3-2 lead at a pivotal point in the game.