Shane Williams was hoping Valentine's Day would be the icing on the cake to his glittering career, but his hopes of getting Mitsubishi Sagamihara Dynaboars into the Top League were well and truly squashed Saturday by Toyota Industries Shuttles.

The Shuttles ran in seven tries in a 53-7 victory to keep their place in the top flight and ensure Williams goes home to Wales empty handed.

"I've tried to get Mitsubishi into the Top League and am sorry we couldn't do it today," Williams said after the game at Mizuho Rugby Stadium.

"I'm more sorry for the players. They've tried really hard but sometimes the big games are too much for them."

In the day's two other promotion playoff games, Coca-Cola Red Sparks and Kubota Spears both retained their Top League status. Cola downed Kyuden Voltex 53-8, while Kubota defeated Kamaishi Seawaves 34-5.

Ryan Kankowski was outstanding, the Springbok No. 8 scored one try, while former Japan center Shotaro Onishi, who is also set to call time on his career, weighed in with six conversions and two penalty goals.

Williams said he hoped to be back over the years to check in with the Mitsubishi players and coaching staff and gave Japanese rugby fans this final message.

"I will hopefully be bumping into you guys in 2019 for the World Cup when I will be supporting Wales and Japan."