Yuma Tongu homered twice, the first a grand slam, to drive in six runs as the Orix Buffaloes beat the Tohoku Rakuten Golden Eagles 9-7 on Tuesday.
The win, coupled with the Fukuoka SoftBank Hawks' 10-3 loss to the Hokkaido Nippon Ham Fighters, moved the Buffaloes back into first place in the Pacific League.
The Buffaloes jumped out to a 5-0 lead in the top of the first inning at Tokyo Dome as Tongu followed a no-out, bases-loaded walk to Leandro Cedeno with his first career grand slam.
Tongu went deep again off former New York Yankees right-hander Masahiro Tanaka (4-5) in the fourth for a two-run shot, making it a 9-2 ballgame.
Hideto Asamura pulled the Eagles within two runs with a grand slam of his own in the fourth, but the rally ended there.
Yuki Udagawa (1-0) won in relief. Yoshihisa Hirano picked up his 13th save.
In the day's other Pacific League game, Gregory Polanco drew a bases-loaded walk in the bottom of the 11th inning, giving the Chiba Lotte Marines a 1-0 walk-off victory over the Seibu Lions.
In the Central League, the Hiroshima Carp trounced the Hanshin Tigers 9-1, the Tokyo Yakult Swallows edged the Yokohama DeNA BayStars 4-3 and the Yomiuri Giants beat the Chunichi Dragons 5-1.