After conceding 19 tries in their opening three matches, D-Rocks restricted the champions to just three during their 22-14 defeat on Sunday, and even harboured thoughts of an unlikely victory when Folau broke through to score from 60 metres out, dragging his side to within five points with five minutes left.
It wasn't to be, but the resilience shown by the competition's bottom-ranked side should give D-Rocks coach Greig Laidlaw plenty to work with throughout the rest of the competition.
So too should the consistent presence of Folau, with the 35-year-old's workload being carefully managed by Laidlaw, who usually brings his star man off the bench.
Injury-plagued in recent seasons, the controversial star has appeared in all four matches played by Urayasu this term after having managed just 22 across the previous three years.
Round four also saw Joseph Manu's Verblitz break through for their first win of the season, coming from behind with two tries in the final 10 minutes to beat Black Rams Tokyo 32-18.
Yokohama Eagles won a high-scoring match against Shizuoka Blue Revs, with Springbok centre Jesse Kriel scoring twice as the Blue Revs suffered their first defeat, going down 53-35.
Saitama Wild Knights are top-of-the-table after a 48-24 win over Mie Heat, which featured hat-tricks by Wild Knights winger Koki Takeyama and his Heat counterpart Lemeki Lomano Lava, as well as a red card for ex Los Pumas captain Pablo Matera.
Tokyo Sungoliath flyhalf Mikiya Takamoto missed a last-minute conversion in his side's 26-26 draw with Spears Funabashi Tokyo-Bay, which leaves Eddie Jones's former club sitting in one of the relegation series positions.
Bernard Foley was a try-scorer for the Spears.
Sunday also proved a good day for the Springbok wingers with Cheslin Kolbe scoring for Sungoliath, while Test teammate Kurt-lee Arendse crossed twice in Sagamihara Dynaboars' 34-26 upset of Kobe Steelers, which condemned former Wallabies coach Dave Rennie's men to their third defeat of the season.
In Division Two, Quade Cooper's Hanazono Liners are winless after three matches following Saturday's 36-17 defeat by the league-leading Red Hurricanes Osaka.
