Right-hander Yuki Koyama allowed a run in eight innings on Saturday as the Central League-leading Yomiuri Giants defeated the last-place Tokyo Yakult Swallows 4-2.
Koyama (6-1) allowed five hits and a walk, while striking out five as the Giants clinched a spot in the postseason. Yomiuri's magic number to clinch its third straight CL pennant dropped to five.
The Giants took the lead in the first inning on a three-run home run by Leslie Anderson, his 11th, off right-hander Taichi Ishiyama (3-7) at Tokyo Dome.