Yasuto Wakizaka opened the scoring for Frontale with a sublime 25-yard freekick after 14 minutes, before Yu Kobayashi doubled their tally a minute after the half-hour mark when he applied the finising touches to a brilliant one-touch passing move with a close-range finish.
Two minutes before the break, Kobayashi struck again with an emphatic volley past Farizal Marlias to effectively end the contest by the break, although the Japanese champions were in no mood to take their foot off the pedal and added further goals in the second half through Marcinho and Chanathip Songkrasin.
The victory was enough to send Frontale top of Group I on eight points, one ahead of JDT who now find Ulsan Hyundai level on points with them following a similarly-crushing 5-0 rout of Guangzhou earlier in the day.
Shandong did manage to pull one back through Lu Yongtao's 76th-minute penalty but Maxime Lestienne made sure they would not mount a late fightback with a third goal for the Singapore Premier League champions with eight minutes remaining, although there would still be time for Liu Guobao to reduce the deficit once more with an exquisite curling effort.
The Sailors are now one of three teams tied on seven points at the Group F summit, following a 0-0 draw between Urawa Red Diamonds and Daegu, with things looking increasingly tight ahead of the final two match days.
BG Pathum can now guarantee their place in the Round of 16 for the second season running in their next game should they beat Melbourne City, who were held to a disappointing 1-1 draw with Jeonnam Dragons having scored in the 89th minute but then conceding in the second minute of injury-time.