The Portuguese superstar went into the game at the Estadio Ciudad de Valencia having scored 13 goals in just six league appearances this season.
And he wasted little time in taking his tally to 14, scoring from the penalty spot after Javier Hernandez had been fouled by Juanfran after 13 minutes.
On-loan Manchester United striker Hernandez got on the scoresheet himself just before half-time with a well-taken header, before Ronaldo added his second of the game and 15th of the campaign with a brilliant individual effort just after the hour.
James Rodriguez got in on the act shortly after, and Isco rounded the scoring off with superb finish from 20 yards eight minutes from time as Real warmed up for a week featuring a UEFA Champions League trip to Liverpool and the season's first Clasico against Barcelona in style.
Ronaldo immediately showed that he meant business, first beating the offside trap to fire wide before sending a low drive whistling past the post within the first five minutes.
And there was a sense of inevitability about Real's opener 10 minutes later.
Some neat play from the visitors resulted in Hernandez bursting into the box, before he was scythed down by Juanfran - allowing Ronaldo to open the scoring with a typically cool spot-kick.
Despite the visitors dominating possession, Levante nearly managed to respond after 25 minutes, with Papakouli Diop’s effort deflected just wide and Luka Modric being forced into a superb goal-line clearance to deny Hector Rodas' header from the resulting corner.
Modric was on hand at the other end to test Diego Marino with a vicious strike from 25 yards 10 minutes before the break, but Real did not have to wait long to double their lead through Hernandez.
A curling cross from Rodriguez found the Mexican unmarked in the box, and he duly marked his first Liga start with his third goal for the club.
Ronaldo continued to be the star attraction after the break, forcing a good save from Marino early in the second half before getting among the goals again after 61 minutes.
A superb run from the left saw Ronaldo skip past several Levante challenges before bursting into the area and finishing with aplomb.
Things got even better for Carlo Ancelotti's side five minutes later when a dinked ball from Toni Kroos found Rodriguez, who chested down brilliantly before poking home.
And Real were not finished there, as Isco took their collective goal tally to 30 from just eight league games when he ran at the heart of the home defence before dispatching a curling shot beyond Marino.