Ronaldo opened the scoring from Karim Benzema's pass on 12 minutes before returning the favour for the Frenchman to slot home six minutes later. The Portuguese added the third from the penalty spot before Bale played in Sami Khedira to make it 4-0 after just 36 minutes.
Antoine Griezmann restored some pride for the visitors with his sixth goal in his last three league games after the break. But Ronaldo rounded off the scoring with a sensational free-kick to take his tally for the season to 24 goals in just 17 games.
Victory moves Real to within two points of neighbours Atletico Madrid and three of leaders Barcelona with the top two both in action on Sunday. "We scored very quickly and so things went very well.
The truth is that after going ahead 4-0, we relaxed a bit and played more slowly in the second-half," Ronaldo told Gol TV. "Overall, I am satisfied with the way we played, although we are not yet at 100 percent, we keep winning."
Another stunning display from Ronaldo led to calls from the Bernabeu crowd for him to win the Ballon d'Or, but he insists he is not concerned by whether he is crowned the world's best player for a second time come January.
"I don't want to talk about the Ballon d'Or. I give my answers on the field. It is something that doesn't depend on me and, therefore, it doesn't bother me that much."
Ronaldo, Bale and Benzema started together up front for the fourth consecutive game after combining for 12 goals and eight assists in the previous three.
And it didn't take the hosts long to get into their stride as Ronaldo fired a dipping long-range effort off the top of the crossbar after just eight minutes.
The Portuguese did then open the scoring four minutes later when he controlled Benzema's clever low cross inside the area before smashing the ball past the helpless Claudio Bravo.
And Ronaldo turned provider moments later as his cut-back from the by-line picked out Benzema inside the box and he stroked home his eighth goal of the season.
It was 3-0 before the half-hour mark as Markel Bergara was harshly penalised for handling Ronaldo's fiercely struck effort and the former Manchester United man stepped up to double his tally for the afternoon.
Bale then passed up his first big opportunity when he side-footed wide after being played in by the impressive Luka Modric.
However, the Welshman made amends nine minutes before the break when he provided his fifth assist in four games by playing in Khedira to fire home from the edge of the area.
With the game already won, Real's intensity dropped a little after the interval and Griezmann thought he should have won a penalty on the hour mark as he looked to have been clipped as he rounded Diego Lopez.
Just 60 seconds later, though, the Frenchman did notch a consolation with a lovely chipped finish over Lopez from Carlos Vela's pass. Griezmann could even have had a second moments later when he prodded just wide of the far post.
Typically, however, Ronaldo was to have the final say as he rattled home a wonderful 25-yard free-kick 14 minutes from time to seal his 23rd hat-trick for Madrid.