Ronaldo's first was a penalty that took him to 100 Champions League goals as a Real player, cancelling out Adrien Rabiot's opener for PSG. He then struck again with the second in the 83rd minute.
Cristiano Ronaldo scored twice as Real Madrid came from behind to beat Paris St Germain 3-1 on Wednesday, with the holders roaring back to life in the Champions League last-16 first leg tie after a dismal domestic campaign.
Adrien Rabiot smashed runaway Ligue 1 leaders PSG ahead in the 33rd minute but Ronaldo levelled from the penalty spot on the stroke of halftime, scoring his 100th Champions League goal for Real to set up a pulsating second half.
Ronaldo put Real in front in the 83rd minute with a scrappy strike from close range, following a cross by Marco Asensio, who made an impressive cameo appearance off the bench.
Brazilian left back Marcelo further stretched the lead in the 86th, giving PSG a tough task in the second leg at the Parc des Princes on March 6.
The tie pitted 12-times European champions Real against the Qatar-backed Parisians who have never gone beyond the quarter-finals in the competition but boasted an attacking trio that cost over 460 million euros($572 million) to assemble in transfer fees alone. The two squads' combined cost exceeded 1.2 billion euros.
"This is a very important victory, these Champions League games are nights you always want to remember and we showed exactly how you need to play," Real captain Sergio Ramos told reporters.
"We showed lots of personality and proved that despite all the speculation about us you can never presume Madrid are dead."
Embattled Real coach Zinedine Zidane has faced serious questions this season with his side falling 17 points behind Liga leaders Barcelona.
He played a master stroke, however, in reverting to almost the same lineup that outclassed Juventus to win last year's final, leaving Gareth Bale out for Isco.