TOKOROZAWA, Japan (Interstat) — The Pacific League’s top two teams meet Wednesday evening at Seibu Dome as the Saitama Seibu Lions host the Hokkaido Nippon Ham Fighters in a pivotal series opener.

The Lions (51-37-1) enter with a 2½-game lead over the second-place Fighters (51-41). Nippon Ham arrives after a 3-0 loss Monday at Orix, where right-hander Kohei Arihara allowed one earned run over six innings in a tough-luck defeat. Arihara, scheduled to start Wednesday, also pitched well in a 9-1 win over Orix on July 2, yielding one earned run over six innings with three strikeouts. He will be a key figure as the Fighters try to close the gap on Seibu.

The Lions counter with catcher Yuto Koga, who drove in three runs with a home run in Monday’s 5-4 win at Rakuten. Koga has been productive of late, going 1 for 2 with an RBI against Orix on July 5 and 1 for 2 against Rakuten on July 8. However, he has also been inconsistent, going hitless in seven of his last 11 plate appearances before Monday.

The teams split a three-game series in Sapporo from July 10-12, with Seibu winning the opener 2-1 and the finale 12-1, while Nippon Ham took the middle game 8-2. Overall, the Fighters hold a 5-4 edge in the season series. Nippon Ham won two of three at Seibu Dome from June 26-28, including a 5-1 victory in the finale.

Interstat’s game simulator projects a 5-4 Lions victory, though its ELO system gives Nippon Ham a 53.4 percent probability of winning. The Fighters will look to Arihara to replicate his strong recent outings and contain a Seibu lineup that exploded for 12 runs in their last meeting.

The game marks the start of a crucial stretch for both clubs, with Nippon Ham beginning a seven-game road trip and Seibu playing six of its next seven at home. First pitch is scheduled for 6 p.m.