Jin Hanato fired in a hat-trick as Yokohama F. Marinos put eight goals past Keio University without reply on Sunday.
Defender Jun Amano and midfielder Jungo Fujimoto scored in the first of two 45-minute halves, before the floodgates opened in the second period.
Striker Hanato produced a dominant performance with his three goals after the break, while Fujimoto, Takuro Yajima and Kensei Nakashima rounded off the landslide win.
F. Marinos slipped eighth in the second stage standings after drawing 1-1 with Shonan Bellmare at the weekend, and will look to pick themselves up when they face Vegalta Sendai on Saturday.