A failed conversion attempt in the 86th minute by fly-half Bryn Gatland has left the semi-final hopes of ex-Wallaby coach Dave Rennie's Kobe Steelers hanging by a thread after a thrilling 40-40 draw with Brave Lupus Tokyo in Japan Rugby League One.

An error-prone Kobe had fought back from a 33-14 halftime deficit to draw level in injury time but the former Chiefs man - the competition's leading point-scorer - missed what could prove his most important kick of the season.

Kobe are seven points outside of the top four, with three matches of the regular season to play.

Brave Lupus were without All Black star Richie Mo'unga, who withdrew on Friday after announcing the death of his father Saimone, but understudy Takuro Matsunaga proved an admirable replacement, critically converting five of his side's six tries.

The win ensured the Todd Blackadder-coached Brave Lupus would join the Robbie Deans-led Saitama Wild Knights as confirmed semi-final entries.

Wallaby winger Marika Koroibete once again underlined what a key man he will be for new Australian coach Joe Schmidt, bagging his second try-scoring double in a week as the Wild Knights fleeced the relegation threatened Black Rams Tokyo 50-26 on Friday night.

The 31-year-old Fijian scored a hat-trick in last year's semi-final and is working into similar form, which will please Schmidt, if not the Wild Knights' opponents.

Fellow Wallaby Bernard Foley endured another frustrating afternoon as Kubota Spears Tokyo Bay were held to a 31-all draw by Shizuoka Blue Revs.

Beaten by an injury time try last weekend against Brave Lupus, the defending champions were all over the Blue Revs in the first half, with the fly-half scoring his second try in as many weeks as part of their 31-0 advantage.

It all turned sour after the break, though, with Foley (around the neck tackle) one of two players sin-binned in the final 10 minutes, as the Blue Revs scored two tries against the remaining 13 men to force the draw.

The home side, for whom dual international Charles Piutau scored twice, will feel they should have won but Keagen Faria suffered the same fate as New Zealander Gatland a day later, scuffing his conversion attempt.

Beauden Barrett was also a double try-scorer as Verblitz beat Sagamihara Dynaboars 34-20 to climb into the top half of the table.

The All Black flyhalf's side trail fourth placed Yokohama Eagles by nine points.

The Eagles beat Hanazono Liners 52-33 on Friday night, while Tokyo Sungoliath outclassed Wallaby Tom Banks' Mie Heat 60-10.