The Portuguese superstar is running out of achievements to notch up in Spain, but he netted his fastest treble in a Real shirt, and his first since December, within 38 minutes of a wonderfully clinical display.
Gareth Bale and Karim Benzema, twice, were also on target for Carlo Ancelotti's side in Madrid, while Diego Mainz put through his own net to compound Granada's misery late on.
Bizarrely given such an emphatic scoreline, Real were far from their fluent best early on.
However, from the moment they led after 25 minutes when Bale's recent upturn in form continued with a well-taken opener under pressure, they never looked back.
Having coolly rounded goalkeeper Oier, Bale registered his fifth goal in four outings for club and country to set the ball rolling, before Ronaldo took centre stage and almost single-handedly put Granada to the sword.
The returning James Rodriguez supplied his first before the Ballon d'Or holder made the most of two Oier errors to register his 24th, and quickest, Liga hat-trick.
The onslaught continued in the second half as Ronaldo scored his fourth in between Benzema's brace, with Roberto Ibanez's late consolation the only disappointment for the hosts.
Mainz then turned Luka Modric's cross into his own net to present Real with another gift, before Ronaldo - fittingly - had the final say to move Real to within a point of Barcelona, who play Celta Vigo later on Sunday.
In their first outing since the international break, Real dominated possession early on but were hampered by loose passes and offside calls.
After Ruben Rochina and Ibanez had both gone close for the struggling visitors, the home fans made their frustrations clear as Granada began to grow in confidence.
But the whistles were silenced when Bale latched onto Toni Kroos’ pass and outmuscled Mainz before rounding the goalkeeper, doing well to keep the ball in play before tucking it into an open net.
The lead was doubled before the half-hour mark, as Granada's early solidity crumbled - Rodriguez cleverly turning a sloppy clearance into an assist for Ronaldo's 32nd league goal of the season.
With Real in full swing, Oier could only parry a fierce Marcelo cross into Ronaldo's path for his second with the visiting goalkeeper also at fault for Real's fourth.
Oier could only help Ronaldo's long-range strike on its way as the Portuguese completed his quickfire hat-trick to take the game well and truly beyond Granada.
Youssef El-Arabi did rattle the crossbar on a foray forward prior to half-time, but it was a rare moment of relief for the visitors as Benzema and Ronaldo continued to expose them after the break.
Showing expert control on his chest, Benzema turned and fired home on the half-volley after 52 minutes to ensure each of Real's frontline a place on the scoresheet, before the Frenchman then turned provider for Ronaldo's fourth.
Benzema took Real's tally to seven himself with Ancelotti subsequently able to withdraw Rodriguez, having made his first appearance since February following a broken metatarsal.
Ibanez finished a quick break for the visitors to ensure a consolation but normal order was restored when Mainz's own goal took Real's tally against Granada to 12 this term.
There was still time, though, for Ronaldo to round off a supreme performance in style as he netted his fifth a minute from time, rising highest to head home Modric's free-kick from the right.
