Cristiano Ronaldo struck twice as Real Madrid retained their Champions League crown and heaped more final heartbreak on Juventus with a 4-1 win in Cardiff.
In a gripping final, Real took the lead when Ronaldo finished off a flowing counter-attack (20) but Juventus hit back seven minutes later through a skilful overhead kick from Mario Mandzukic that will go down in history as one the greatest goals in Champions League history.
Ronaldo's CL goal-scoring brilliance
Cristiano Ronaldo underlined his status as the Champions League's greatest goal-scorer against Juventus.
Casemiro fired Zinedine Zidane's side into the lead on 61 minutes and Ronaldo - who now has 600 goals for club and country - struck again three minutes later, before Marco Asensio wrapped up a convincing victory in stoppage time to seal a historic 12th European major title for Real.
Juve - who had substitute Juan Cuadrado sent off for two yellow cards late on - have now suffered a fifth straight defeat in the showpiece European final (1997, 1998, 2003, 2015, 2017) but victory for the La Liga giants means they have become the first side to defend the Champions League since its revamp in 1992.
This fixture matched up a well-drilled Juventus defence that had conceded just three goals in this season's competition against a ruthless Real attacking outfit that scored in all of their 12 Champions League matches this season.
Gareth Bale was deemed only fit enough for a place on the bench as Zidane made just one change from their La Liga win on the final day of the season, Dani Carvajal starting over Danilo at right-back.
Massimiliano Allegri's side showed no signs of nerves as they tested Keylor Navas with two early efforts inside six minutes with Gonzalo Higuain, who had never scored in a major final, and Miralem Pjanic firing efforts that were dealt with by Navas.
Juventus looked comfortable while Real were struggling to put their stamp on the game. That all changed on 20 minutes when a clinical finish from a familiar source swung the final in their favour.
Ronaldo had netted three goals in four competitive matches at the Principality Stadium - all with Manchester United - and added another to that tally with a crisp strike following a flowing counter-attack down the right flank.
Carvajal cut the ball back into his path and the record-breaking striker fired a low effort into the bottom corner that took a slight deflection off Leonardo Bonucci.
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But Juve drew level seven minutes later through Mandzukic - and it was one to remember. Higuain knocked the ball to his team-mate, who had his back to goal - about 15 yards out. After taking a touch, he cleverly hooked an effort towards the far corner which looped into the top corner.
Juventus continued to play the better football, although they failed to test Navas with any meaningful efforts. Both teams were threatening to cancel each other out and the game needed a spark.
It came from an unlikely source on 61 minutes.
Casemiro - known for tough tackling and breaking up play rather than match-winning goals - smacked an effort at goal from 25 yards and though it was not particularly well struck, the direction of the ball completely changed when it struck the heel of Sami Khedira. The spin deceived Buffon and the ball ended up swerving into the bottom corner.
Juve would have been forgiven for thinking that it may not be their night but things got a whole lot worse three minutes later.
Mandzukic was too slow to react a pass deep inside his own half and Modric made a clever run down the right flank, digging a cross out from the byline that allowed Ronaldo to nip in at the near post and flick past Buffon. Two chances, two goals.
That completely deflated Allegri's men and Cuadrado summed up their frustrations by picking up two needless yellow cards within five minutes of being sent on.
Bale was introduced for the closing stages to give some of the locals a glimpse of their hero, but it was another substitute, Asensio, that grabbed the fourth goal after some brilliant work by Marcelo, Zidane's side becoming the first side to retain the trophy for 27 years.