The Portuguese ace was unstoppable...
Los Blancos stormed into the lead through Gonzalo Higuain and Cristiano Ronaldo in the first half-an-hour and Fernando Llorente clawed one back for the visitors before the break.
Bilbao fought vailiantly, but ultimately fell victims to a well-taken penalty by Sergio Ramos, a free-kick and spot-kick from Ronaldo in the second half as Jose Mourinho's men bagged the three points.
The visitors made a very good start to the game with Llorente actively involved in every attack. The Spanish international saw an effort cleared off the line only three minute into the game after a blistering run on the right side of the box.
It took some time, but Real Madrid started to grow into the game and were looking threatening in the final third. The go-ahead goal came in the 19th minute when Higuain slotted home with a fine finish, following some good work by Angel Di Maria.
Athletic tried to put Los Blancos under pressure with Llorente forcing Iker Casillas into a fine save in the 29th minute. Los Leones ultimately paid the price for their somewhat overly attacking approach moments later when Ronaldo doubled the hosts' lead after an excellent counter-attack.
In the 40th minute Llorente managed to halve Los Leones' deficit with a goal from point-blank range after a collective mistake by the home defence. Real Madrid entered half-time with a tender lead as the match was far from over.
The game's tempo somewhat dropped after the restart as both teams seemed unwilling to take any risks. Still, the Madrid were more comfortable on the ball and were superbly retaining possession in the early minutes of the game.
Ramos put the game to bed for the Los Blancos in the 57th minute from the spot after an arguably soft penalty for a foul on Di Maria by Markel Susaeta. Athletic started pumping bodies forward, but were unable to break Real Madrid's resilient defence.
Ronaldo put the icing on the cake with an audacious free-kick in the 62nd minute to complete his brace. The visitors had not given up yet as they tried to get back into the contest and nearly scored in the 85th minute when a Javi Martinez' shot rebounded off the bar.
In the 88th minute substitute Karim Benzema had the ball in the net, but it was ruled out for offside. Ronaldo, however, had more for Los Leones as he completed his hat-trick from the spot after a foul on substitute Esteban Granero in injury time.