Portugal 4-0 Luxembourg The Portuguese made it eight wins from eight in Portimao, but scored three of their goals late on.
Portugal dominated but had to wait until the 70th minute to make the game safe as Varela collected the ball, jinked past his marker in the area and left Mond with no chance. The final two goals arrived in the final two minutes, Quaresma and João Pereira providing the gloss.
Portugal face second-place Russia on Tuesday, knowing a draw will be enough to win the pool. Luxembourg remain bottom with one point from eight games.