Right-hander Shun Yamaguchi held Central League-leading Yomiuri Giants to an unearned run over six innings, and veteran Hitoshi Tamura hit a two-run homer on Wednesday as the Yokohama BayStars beat the Giants 6-2.

Yamaguchi (4-3), the BayStars former closer, allowed four hits and a walk, while striking out two before a crowd of 28,186 at Yokohama Stadium. Yamaguchi, who was thrust into the starting rotation in June, won three straight starts and pitcher of the month honors, won for the first time since June 15.

"I was just thinking about pitching so the team could win," said Yamaguchi. "It was a good thing I could shut them down after being given a lead and having some good plays made behind me. I was given the ball while we are on a roll and am glad we could win. I'm also glad it didn't go to extra innings, because my last three starts all went to extra innings."