Munakata Sanix Blues remained on course to win the Top Challenge Series on Sunday with a 61-14 victory over Kyuden Voltex at Prince Chichibu Memorial Rugby Ground.
Karne Hesketh — who scored Japan's winning try against South Africa at Rugby World Cup 2015 — crossed twice as did Benjamin Yagi and Bryce Robins, who played for the Brave Blossoms at the 2007 and 2011 World Cups.
The win followed last week's 48-18 victory over Mitsubishi Sagimihara Dynaboars.
In the past, the winner of the four-team tournament — which sees the three regional champions and the best runnersup battle it out — would have won automatic promotion to the Top League.
But with the season being shortened as a result of last year's World Cup and the Sunwolves' entry into Super Rugby, the format is slightly different.
This year, the winner of the Top Challenge Series, which concludes next week, will play the team that finishes bottom of the Top League. The second-place team in the TCS will take on No. 15 from the TL, while the third- and fourth-placed regional teams will play the teams that finished 14th and 13th in the top flight, respectively.
Following Saturday's Top League playoff games, Coca-Cola Red Sparks will take on Ricoh Black Rams on Jan. 23 for 13th spot, while NTT Docomo Red Hurricanes face NEC Green Rockets for 15th.
"It's pretty unlucky because normally we would have won (the TCS) and a place in the Top League," said Sanix prop Shin Dong-won. "But whatever Top League side we play will have everything to lose."
When asked which of NEC and Docomo he hopes to face, Hesketh said, "We don't have a say in who we play. It's up to them who finishes last."
In the second game of the day's doubleheader, Mitsubishi ran in eight tries in a 54-19 victory over Osaka Police, who opened their campaign with a 31-3 loss to Kyuden.