A late brace by substitute Taiki Koyama earned Panasonic Wild Knights their fifth bonus-point win of the season, a 46-27 victory over Toshiba Brave Lupus on Saturday.

The late charge at Kumagaya Sports and Culture Park, enabled by a steady stream of defensive lapses, saw the Top League leaders erase a 27-22 deficit following Jone Naikabula's 50th-minute try for Toshiba.

Ryota Hasegawa, former Wallaby Daniel Heenan and Australian Dylan Riley each scored tries first-half for Panasonic, who took a 22-17 lead into the break.

Daigo Hashimoto's try leveled the scores six minutes after the intermission, and four minutes later Naikabula crossed after a long throw-in on a lineout took the Wild Knights by surprise.

But most of the day's surprises were spring by Panasonic, whose dummies frequently unhinged the Brave Lupus defense. A bruising run to near the try line by David Pocock set up Takuya Yamasawa for a soft try. Rikiya Matsuda, who kicked 11 points, added the extras to make it 29-27.

Koyama then scored twice on dummies, running into space as soon as the nearest defender took his eyes off him.

(Taiki Koyama celebrates scoring a late try for Panasonic Wild Knights)

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The loss was Toshiba's first of the season and left them fourth, seven points behind the Wild Knights.

Kobe Kobelco Steelers stayed two points back of Panasonic with a 43-6 win over Ricoh Black Rams with Shintaro Hayashi bagging a brace and Hayden Parker scoring eight with the boot.

Third-place Yamaha Jubilo crushed NTT Docomo Red Hurricanes 82-7 with Jayden Ngamanu and Malo Tuitama each scoring a hat-trick of tries.

Fifth-place Suntory Sungoliath likewise pounded Toyota Verblitz, who could not score until the 70th minute of a 60-14 demolition.

Elsewhere, NTT Communications Shining Arcs scored 12 tries in a 74-11 win over Munakata Sanix Blues, while Honda Heat beat Canon Eagles 39-24.