The Brazilian fired home from 35 yards six minutes into the second half before turning provider to lay on the second for Issam Jemaa.
Al Qadsia saw plenty of the ball and created numerous chances but had to settle for the runner-up spot for the second time in four years.
Omar Al Somah almost handed Al Qadsia the lead in Kuwait City, hitting the post with a powerful header after 16 minutes.
That was as close as either side came to breaking the deadlock in the first half but the game was illuminated by Rogerinho in the 51st minute.
He collected the ball midway inside the opposition half and advanced unopposed before unleashing an unstoppable long-range drive.
Just eight minutes later it was 2-0, Rogerinho doing the hard work down the right-hand side before squaring for Jemaa, who had the simplest of tasks to apply the finish.
Al Somah spurned an opportunity to reduce the deficit late on as Al Qadsia were left to rue missed chances.
