Western Sydney's Asian Champions League campaign is effectively over after a 6-1 shellacking at the hands of Urawa Red Diamonds, their biggest loss in Asia.

Five days after their A-League season ended in Brisbane, the Wanderers were outclassed in Japan, repeatedly ripped apart at Saitama Stadium reminiscent of their opening 4-0 loss in Campbelltown.

Despite a mini second-half fightback underpinned by Jumpei Kusukami's first goal since January, Tony Popovic's side remain tied to the bottom of Group F with one match remaining against Shanghai SIPG.

The Wanderers needed not only a win against the group leaders but a hatful of goals to remain even an outside chance of progressing as one of the top two teams.

The goals did come on Wednesday, just not at the right end, as Popovic's experimental three-man defence proved no match for the diligence and ruthless attack of the J-League leaders.

AAP