Ronaldo's strike eight minutes from time ensured Real claimed a 2-2 draw with Atletico at Estadio Vicente Calderon to remain three points clear of their fierce city rivals at the top of the Primera Division.
Atletico looked on course for the derby bragging rights after first-half strikes from Koke and Gabi had put them ahead following Karim Benzema's early opener for Real.
But Ronaldo lashed home in the 82nd minute to the relief of boss Carlo Ancelotti and deny Atletico's hopes of completing a league double over their more celebrated rivals for the first time since 1951, having beaten them at the Bernabeu 1-0 earlier in the season.
Real could yet find their advantage cut to one point by the end of the evening should Barcelona beat unfancied Almeria, although they may be pleased to walk away with something after a battling performance.
They came into this contest in high spirits after thumping Schalke 6-1 in the Champions league earlier this week and their momentum carried on into Sunday night, with Benzema scoring in the third minute.
The French striker beat the offside trap to poke home from close range at the back post after Angel Di Maria crossed from the right to give Real a dream start.
Atletico would have felt aggrieved not to have been awarded a penalty soon after, though, after Sergio Ramos appeared to knock Diego Costa to the ground, but referee Carlos Delgado Ferreiro rather emphatically waved play on.
Raul Garcia sent his effort from distance well wide and Costa narrowly missed the target with his effort from just inside the area, while at the other end, Ronaldo's cheeky backheel was pawed away by Atletico goalkeeper Thibaut Courtois.
Los Rojiblancos hauled themselves level in the 28th minute when Koke picked up Arda Turan's ball on the right side of the penalty box before steadying himself and drilling across the helpless Diego Lopez.
Costa continued to cause problems for Real's defence, but it was Gabi who gave the hosts the lead with a magnificent strike from all of 30 yards that fizzed into the top corner, with Lopez perhaps a touch unsighted by all the bodies in front of him.
Diego Simeone's men continued to be the more threatening after the interval, knowing they could draw level with their opponents with victory and it was once again Costa driving forward before shooting wide from the edge of the area.
Real nearly equalised through Benzema, who steered a volley from close range just wide of the post, while Gareth Bale's header from Di Maria's free-kick was smartly saved by Courtois.
Costa should have doubled Atletico's lead but saw his effort from point-blank range somehow steered onto the bar by Lopez, who kept his side in the match with his brilliant reaction save.
Ronaldo wasted a decent opportunity to level matters after heading wide but he then atoned for his miss late on by driving low into the corner with his left foot from just inside the area.