Sungoliath demolished Yokohama Eagles 54-22 on Sunday despite going down to 14 men when second rower Sam Jeffries was red carded four minutes after halftime.
Yokohama, who had trailed 20-12 at the time, scored 10 points in the next six minutes to edge ahead before the 31-year-old Nudgee College (Brisbane) product - who played 27 Tests for Australia between 2014 and 2017 - scored two of the game's final six tries to shore up the win.
Israel Folau followed last week's hat-trick with two tries, but underrated Queenslander Isaac Lucas had the last laugh as BlackRams Tokyo claimed an important 41-19 win over Urayasu D-Rocks.
The 27-year-old Lucas, whose elder brother Ben played for the Wallabies, is eligible for Japan on residential grounds, and continues to catch the eye, scoring a try just after halftime yesterday that started his side's scoring spree.
Former Australia and Queensland backrower Liam Gill also touched down before the game ended as the BlackRams piled on 29 points to five in the second half.
Black Rams meet Brave Lupus Tokyo in the next round.
Brave Lupus are in trouble, sliding to their third consecutive defeat on an astonishing afternoon in Aichi where Steve Hansen's Verblitz, who had previously won just one match, demolished the defending champions 52-21.
The Dave Rennie-coached Kobe Steelers are up to second after swamping Saitama Wild Knights 40-24, inflicting the latter's first defeat of the season, and heaviest in the five years since League One began.
Bernard Foley's Spears Funabashi Bay top the leaderboard after a 26-10 win over Sagamihara Dynaboars, while Semi Radradra's Shizuoka BlueRevs were beaten 26-21 by Mie Heat.