Tokushima Vortis will battle Shonan Bellmare for a place in the J. League first division after beating J2 playoff opponents Montedio Yamagata 1-0 on Sunday.
Forward Atsushi Kawata struck in the 53rd minute at Pocari Sweat Stadium to send Vortis into the promotion-relegation playoff final on Saturday against Bellmare, who finished 16th in the J1 standings.
Tokushima's winner came after the hosts went the length of the field from a goal kick, with Kawata running onto a superb through ball from forward Naoki Nomura and deftly chipping Yamagata keeper Masatoshi Kushibiki from the edge of the box.
"It definitely felt like there would be chances, so when one came my way, I was glad to score," Kawata said.
"We've improved a lot this season, and continued it into these playoffs."
Under the playoff format introduced last year, teams finishing third through sixth in the J2 meet in an elimination series, culminating in a match against the 16th-ranked J1 side for a place in the top flight.
Fourth-place Tokushima advanced past fifth-place Ventforet Kofu in the opening round, while sixth-place Yamagata sprang an upset on the road against third-place Omiya Ardija.