Daniel Miller put the Levanga Hokkaido ahead for good in the final minute of overtime on Wednesday in their 75-70 triumph over the host Akita Northern Happinets.
Miller's jumper and subsequent free throw gave his club the narrowest of leads, 71-70, with 40 seconds to play.
Veteran sharpshooter Takehiko Orimo, now 46 years old, sank four free throws down the stretch to seal the win for Hokkaido (5-12).