The hosts dominated possession in the first half but, perhaps missing the influence of key quintet Luka Modric, Toni Kroos, Marco Asensio, Sergio Ramos and Marcelo, found it hard to create chances until Benzema's clever back-heel found Ronaldo, who span and shot to open the floodgates.
Alaves have also been in fine form, winning three consecutive league games for the first time this season. John Guidetti kept his spot in the final third, but he had a new partner as Ruben Sobrino came in for Munir El-Haddadi. Ceballos, a 10-million-euro signing from Real Betis last summer, has made only two Liga starts since joining Madrid.
Benzema was again the creator as Bale made it two less than a minute into the second period.
Benzema missed another sitter moments later when he hit the post from close range, but the offside flag just about spared the Frenchman's blushes.
Alaves had done well to hold their own, but within moments of the second period starting, a mistake from Alexis allowed Benzema to nip in and set up Bale for a simple finish.
Karim Benzema and Cristiano Ronaldo. FELIPE SEVILLANO
On Real's recent return to form with four straight wins, Zidane added: "It is clear that we have character, personality and to score 26 goals in six games is very good". Alaves are in the bottom third of the table but have very little chance of being relegated.
Ronaldo spun inside the box before firing a powerful effort into the bottom corner.
Theo Hernandez brought a smart save from Pacheco in the 66th minute as the pressure continued, before Lucas smashed the ball into the side-netting five minutes later.
Ronaldo, who made it 12 goals in his last seven games with his two goals, handed over the chance of his hat-trick from the penalty spot as Benzema swept in his fourth league goal of the season to complete a flawless afternoon for Zidane.
They have scored 30 goals and turned the heat up on second-placed Atletico Madrid.