Shane Williams was hoping Valentine's Day would be the icing on the cake to a 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. Coca-Cola downed Kyuden Voltex 53-8, while Kubota defeated Kamaishi Seawaves 34-5.

Riddled by errors and injuries, Mitsubishi were unable to match the physical intensity and pace of the Shuttles, for whom 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 — the IRB World Player of the Year in 2008 — started the game on the bench and entered the fray in the 69th minute. Two minutes later he showed some of the dazzling footwork and speed that saw him win 87 caps for Wales, four for the British and Irish Lions and finish his international career as the third-highest try scorer in test history. But he was unable to give the crowd what they wanted — a farewell try.

"It's my third year here and it's certainly something three years ago I didn't think I would be doing," Williams said. "It's been one of the best experiences of my life and I've enjoyed every minute of it. But it's time to go home and be with my family."

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."