Ronaldo nets 2 as Madrid beats Alaves 4-0 in Spain
Benzema set up both Ronaldo's opener and a quick second goal by Bale to put the result beyond doubt seconds after halftime.
Benzema used a subtle touch with the back of his heel to leave Ronaldo in position to drill the hosts' first goal into the net in the 44th minute.
The French striker helped to double the lead less than 30 seconds into the second half after he stole possession from Alexis Ruano, catching Alaves defending a four-on-two attack. Benzema laid off for Bale to fire past goalkeeper Fernando Pacheco.
Ronaldo got in his second goal in the 61st when he used one touch of his right boot to fire Lucas Vazquez's pass under Pacheco.
Benzema converted a penalty in the 89th after Bale was fouled by Victor Larguardia in the area.
Bale played in a new position for Madrid, as a left-side midfielder as opposed to his usual spot as a winger on the right.
Besides scoring and generating a penalty, the Wales international went close to a second goal in the 54th when he curled a long strike that grazed the top of the bar.
''I wanted to see him in that position and now we see how we play in the upcoming games,'' coach Zinedine Zidane said. ''Playing with a 4-4-2 with Bale on the left worked well because Alexis (Ruano) couldn't join in attack. Then when we had the ball he had to move and not stay on the left and he did that well. Bale, Cristiano, Karim, Lucas, everyone played well as a group.''
Ronaldo's goals were his 27th and 28th of the season in all competitions and took his tally in La Liga to 14.
Madrid, in third place, trails leader Barcelona by 14 points.
Ruano had Alaves' best opportunity in the final seconds of the first half after Ronaldo scored, only for goalie Keylor Navas to block his effort.
''You build your confidence with games like this,'' Zidane said. ''Maybe we needed a game like this.''
With scant hopes of successfully defending its Liga title, Madrid is focused on repeating as the winner of the Champions League. It beat Paris Saint-Germain 3-1 in the first leg of their round-of-16 tie last week. It has league matches against Espanyol and Getafe before visiting Paris on March 6.