Last season's beaten finalists were big favourites to reach the showpiece after claiming a 4-2 victory in the first leg a fortnight ago.
And Al Qadsia sealed their progress to a third final in style, as the Kuwaiti champions ran riot in Jayapura.
Saif Al Hashan got the visitors off to a flying start at the Stadion Mandala as he broke the deadlock after just six minutes, before Bader Al Mutawa doubled their advantage just after the half-hour mark.
Al Hashan added his second of the game 11 minutes after the break and, not to be outdone by his team-mate, Al Mutawa did the same with 17 minutes remaining.
Khaled Ebrahim then got in on the act to make it 5-0, before Saleh Al Sheikh rounded matters off in the last minute.
Al Qadsia will face either Erbil or Kitchee in the final.
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