Robbie Deans has won the battle of the former Wallaby coaches in Japan Rugby League One, with his Saitama Wild Knights beating Dave Rennie's Kobe Steelers 46-32 to extend their lead at the top of the table to six points.

Australian-schooled back-rowers Jack Cornelsen and Ben Gunter were both among the try-scorers for the winners.

Their efforts backed up a masterful performance from Springbok inside centre Damien de Allende, who crossed twice, while also setting up a try for former Wellington Hurricanes winger Vince Aso.

Kobe, who have not beaten the Wild Knights in 22 years, must have thought this was their time when they scored tries either side of halftime to lead 32-20.

However, three tries in a devastating six-minute period between the 57th and 63rd minutes blew away those hopes.

Shizuoka Blue Revs (fourth) and Yokohama Eagles (fifth) retained their places in the top six after Sunday's wins over Mie Heat and Tokyo Sungoliath, with the Eagles' 33-22 success in Tokyo seeing them jump one place above Kobe on the standings.

On Saturday Wallabies Bernard Foley and Samu Kerevi were each yellow-carded.

Kerevi's second card for a dangerous tackle in three weeks came during bottom-placed Urayasu D-Rocks' nail-biting 36-31 defeat by Steve Hansen's Verblitz.

Foley was sent to the sidelines for his team's repeated infringing as the third-placed Spears Funabashi Tokyo Bay fell short in a 31-27 loss to Brave Lupus Tokyo.

The sanction was part of a mixed afternoon for the ex-Wallaby flyhalf, who played a leading hand in two of the Spears' tries but missed two conversions, which proved vital.

Verblitz romped ahead 28-0 but got the wobbles defensively as Kerevi's side roared back into the contest, although Steve Hansen's side held on to secure their second win of the season.

Black Rams Tokyo continued their recent improvement, accounting for Sagamihara Dynaboars 22-7, with former Australian under-20 winger Semisi Tupou touching down for the third week in a row.

In Division Two, tries by former Wallabies Quade Cooper and Will Genia, along with All Black Akira Ioane, were not enough as Hanazono Liners were beaten 36-29 by former All Black Lima Sopoaga's Koto Blue Sharks.