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The reigning champions went ahead in the 14th minute when James Rodriguez played Nacho behind the Basel defence with a neat back-heel, and the defender's cross was turned into his own net by Marek Suchy.
Carlo Ancelotti's side nearly doubled their lead when Pepe's headed effort from a corner was fumbled by Vaclik, but no Madrid player managed to turn the ball into the net before the keeper could punch it away.
Madrid did get their second goal when Luka Modric picked out Gareth Bale with a pinpoint pass, and the Wales international showed composure to lift the ball over the keeper before placing the ball into the net.
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The home side continued to display their clinical edge in front of goal as Ronaldo added a third goal by latching on to Bale's cross into the box and slotting the ball into the net.
Madrid continued to find the net with ease as they made it four when Karim Benzema and Ronald linked up to see the Frenchman fire an effort at goal, and although his effort was saved James Rodriguez was on hand to turn in the rebound.
In the second half, the visitors threatened first as Madrid failed to clear their lines from a cross into the box and Luca Zuffi reacted first, but he couldn't muster any power on his shot and Casillas saved with ease.
Basel should have reduced the deficit to two goals when Raphael Varane's header back to Casillas was poor and allowed Gonzalez a one-on-one opportunity, but the keeper made a great stop to deny the striker.
The Swiss continued to threaten as Fabian Schar picked up the ball outside the area and drilled an effort off the post.
However, Madrid killed the game off in their next attack when Ronaldo teed up Benzema, who rifled his shot past Vaclik with the aid of the crossbar.