The Mitsubishi Heavy Industries Sagamihara Dynaboars made the leap into the Top League on Sunday with a 31-7 win in their relegation-promotion game against the Toyota Industries Shuttles on Sunday.
Daniel Hawkins kicked 16 points, while Yuderyckenys Thomas, Yoshimitsu Yasue and Matt Vaega scored tries at Nagoya's Paloma Mizuho Rugby Stadium to return the Dynaboars to the top flight for the first time since the 2007-2008 season.
Elsewhere, the NTT Docomo Red Hurricanes returned to the Top League after one season in the second tier with a come-from-behind 33-24 win over the Coca-Cola Red Sparks, facilitated by two yellow cards within a span of six minutes in the second half.
With a numerical advantage, Mewett Keepa scored a brace of tries to put the Red Hurricanes up. Koki Shigeno's 33rd-minute try iced his team's promotion.
The Munakata Sanix Blues and Hino Red Dolphins also remained in the top flight, with Blues smashing the Kurita Kogyo Water Gush 75-0 and the Red Dolphins keeping longtime Top League club Kintetsu Liners in the second tier with a 21-11 win.