TOKYO -- 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.
Iwakuma spent 12 seasons in Japanese professional baseball before signing with the Mariners during the offseason. He gave up five more runs before leaving after the fourth.
Seattle is in Japan to open major league season against the Oakland Athletics on Wednesday and Thursday.
The Mariners and Iwakuma agreed to a one-year, $1.5 million contract last month, plus $3 million in performance bonuses bases on starts and innings. He would get the full amount with 32 starts and 200 innings, but Seattle manager Eric Wedge already has said Iwakuma will start the season in the bullpen.
Iwakuma took the loss, allowing 10 hits with no walks and one strikeout.
"I don't think the pressure of pitching here got to him," Wedge said. "He threw the ball well but couldn't make the pitch to finish off batters. If he does that it's a different ballgame."
Ichiro Suzuki was 0 for 4 but made a fine defensive play in the fifth inning that drew cheers from the near-capacity crowd of 43,759. With runners at first and third, the right fielder caught a deep fly ball off the bat of Yoshiyuki Kamei and held a runner at third with an accurate throw to the plate.
Houlton, who got the win, gave up two runs and three hits in five innings.
Seattle lost both of its exhibitions against Japanese opposition but Wedge said he wasn't worried about his team.
"It's a completely different atmosphere here and, obviously, we didn't play good baseball," Wedge said. "But we had a good spring and I trust my guys and I'm sure we'll turn the switch on for opening day and be ready to go."
Yomiuri took a 2-1 lead in the second on Kenji Yano's double, but Seattle tied it in the third when Ackley tripled leading off and scored on Suzuki's groundout.
Shuichi Murata, one of Yomiuri's big offseason signings, hit a two-run single with two outs in a four-run third, and Hayato Sakamoto had a two-run single in the fourth for a 6-2 lead.
Kyle Seager singled in a run for Seattle in the sixth, but the Giants boosted their margin to 8-3 in the bottom half when Hisayoshi Chono scored from third on a passed ball by Guillermo Quiroz and Takahiro Suzuki stole home.
Kamei had a solo homer in the seventh against Charlie Furbush.