Juventus manager Massimiliano Allegri said even his side's rock-like defence was powerless to resist Real Madrid's firepower as the Italian club's hopes of a first Champions League triumph in 21 years ended in heartache on Saturday.

The Italian champions' defensive wall had been almost impregnable all season in Europe but was reduced to rubble as Real roared to victory with three goals after the break.

"In the first half we played beautifully but they pushed the accelerator in the second half and we could not resist," Allegri, whose side had been bidding to become the eighth club to land the "treble" having won Serie A and the Copa Italia this year, told reporters.

Juventus leaked three goals in 12 games en route to the final, twice shutting out Barcelona's feared attack in the quarter-finals before blunting a free-scoring Monaco strike force in the semis.

But the granite-like trio of Giorgio Chiellini, Andrea Barzagli and Leonardo Bonucci cracked after Juventus had been the better side in a first half that ended 1-1.

"The two goals in quick succession hurt us and we were not able to react," Allegri said.

"The only criticism I could make is that after the second goal we should have stayed in the game mentally to make sure we still had chances."

In a sizzling first half, Cristiano Ronaldo put Real ahead before Mario Mandzukic's incredible overhead kick, one of the great European Cup final goals, deservedly drew Juventus level under the Principality Stadium roof.

Juventus retreated after the break, though, and Casemiro's deflected strike restored Real's lead on the hour before Ronaldo struck the killer blow three minutes later.

After substitute Juan Cuadrado was sent off, Marco Asensio rubbed salt into Juve's wounds as they fell to their fifth successive defeat in a Champions League final.

"I had to take some risks tonight," Allegri said. "We had to try to score a goal, get ahead, and then defend in the second part of the game. But we were not able to do that.

"With a bit more luck we could have finished the first half in the lead and then it would have been a different match."

With keeper Gianluigi Buffon close to 40, Barzagli 36 and Chiellini and Bonucci the wrong side of 30, it is tempting to suggest that Juve's rearguard will soon need rebuilding.

Allegri, however, said the crushing defeat was far from the end of the road for his side.

"No I don't think Juve has reached the end of a cycle at all," Allegri said.

"Buffon will still be goalie next season and Barzagli with be with us for another year. They still have lots to give this club. But we can improve the team.

"We all need to rest now but after the holidays we will return with new drive and stimulus."