Hisashi Iwakuma had a shaky return to Japan, giving up six runs over four innings Monday in Seattle's 9-3 exhibition loss to the Yomiuri Giants -- the last game for the Mariners before their season opener. Dustin Ackley hit a solo homer in the first off D.J. Houlton at Tokyo Dome. Former Philadelphia Phillies outfielder John Bowker tied it when he homered off Iwakuma in the bottom half.