Faced with the seemingly impossible task of scoring three goals without reply at the Bernabeu to force extra time, Juve got off to the perfect start as Mario Mandzukic - handed a start in place of the suspended Paulo Dybala - rose unmarked at the far post to convert Sami Khedira's cross from the right with less than two minutes gone.
April 11, 2018
Keylor Navas was called into action just minuted later to smother Gonzalo Higuain's effort as the visitors came flying out of the blocks.
However, Real did have the ball in the net with 14 minutes gone, only for Isco's effort to be chalked off for offside.
The hosts were the next to threaten as Ronaldo slippind Isco in on goal but Gianluigi Buffon began what would be an eventful night with a smart stop at the near post to deny the Spaniard.
- Mario Mandzukic, record breaker -
With eight minutes to go until the break, Juve found their second of the game. Stephan Lichtsteiner - an early replacement for Mattia De Sciglio was given space to cross down the right and Mandzukic got up above Dani Davajal at the far post to power a header inbetween the post and the outstretched hand of Navas to double the visitors' lead and put them within a goal of forcing extra time.
April 11, 2018
On the stroke of half-time the hosts were within inches of a key goal as Raphael Varane rattled the crossbar with a header from a Toni Kroos free-kick.
Nevertheless, Juve went in two goals to the good at the break, sparking a daring double change from Zinedine Zidane as Marco Asensio and Lucas Vazquez replaced Casemiro and Gareth Bale.
Both sides had chances in the early exchanges of the second half with Ronaldo seeing a low effort well gathered by Buffon and Navas having to be alert to deny a similar strike from Higuain.
- Navas clager -
It proved to be a case of from the sublime to the ridiculous, though, for the Costa Rican just minutes later as he allowed the impressive Douglas Costa's ball in from the right to slip through his grasp and fall at the feet of Blaise Matuidi to put Juventus level on aggregate and on the verge of dreamland.
A Juventus goal at that point would have left the hosts needing two to progress but it was 'Los Blancos' who piled on the pressure, Isco's low effort from the edge of the box forced Buffon into a fine save after taking a nick off Medhi Benatia. Whilst Raphael Varane saw an effort on the turn flash narrowly wide of the far post from the ensuing corner.
At that point we looked destined for 30 extra minutes, but it wasn't to be.
In the last of the three minutes added on at the end of the 90, Benatia was adjudged to have come through the back of Vazquez as he attempted to convert Ronaldo's header back across goal and Michael Oliver pointed immediately to the spot. The decision saw incensed Juventus players immediately surround the referee, with the usually mild-mannered Gianluigi Buffon sent off for his aggressive approach to the official.
April 11, 2018
Despite five minutes passing between the decision and the penalty being taken Ronaldo kept his cool to fire the spot-kick into the top corner and send Real Madrid through to the semi-finals of their favourite competition, where they will be joined by Liverpool, Roma and Bayern Munich.
It was harsh on the Italians, who had given it everything in their attempts to ensure a famous comeback victory. It seems particularly disappointing that Buffon's Champions League career looks set to end with a red card.