Daisuke Kusano hit a tiebreaking two-run single and Norihiro Nakamura added a two-run double in the fifth inning, leading the Rakuten Eagles to a 6-3 win over the Seibu Lions on Wednesday.
Surprise Pacific League leader Rakuten has now won four three-game series in a row and holds a two-game lead over the second-place Nippon Ham Fighters, who lost to the Lotte Marines 7-3.
"We took the series two games to one against the defending champions. There are mysterious forces at work," manager Katsuya Nomura said after Rakuten moved eight games over .500 for the first time in club history.