Ronaldo put the Bianconeri ahead on 26 minutes after getting on the end of Federico Bernadeschi’s cross.
Three minutes after the break, his header was adjudged to have crossed the line by goal-line technology and he sealed the hat-trick from the penalty spot with just five minutes to go to seal a memorable comeback.
The Video Assistant Referee (VAR) system had already played a huge part in deciding Manchester United and Ajax’s memorable comebacks last week and it featured at the Allianz Stadium inside the first four minutes.
The Italian champions overturned a two-goal deficit from the first-leg in Spain thanks to a Cristiano Ronaldo hat-trick on a feverish night in Turin.
Ronaldo headed home in the 27th minute and then the 49th before thumping home from the penalty spot with four minutes remaining after Fernando Bernadeschi was fouled by Angel Correa.
Cristiano Ronaldo thumps home from spot to ensure Juventus’ progress to the last-eight of the Champions League
Ronaldo’s hat-trick completed an incredible comeback from the Italian giants after losing the first leg 2-0 in Madrid
Cristiano Ronaldo heads his second goal of the night despite the best efforts of Jan Oblak to keep it from crossing the line
Ronaldo’s goal was awarded by goal line technology as Juventus drew level on aggregate four minutes after half-time
Ronaldo is mobbed by team-mates after his second goal set up a grandstand finish at the Juventus Stadium on Tuesday night
Cristiano Ronaldo towers over Diego Godin in the air to score the opening goal of the night for Juventus before the half-hour
Ronaldo celebrates after breaking the deadlock from Federico Bernadeschi’s cross to the far post after 27 minutes