Cristiano Ronaldo, the leading scorer in the Champions League for five years running, contributed two goals as Real Madrid won the title for the 12th time here on Saturday night, reports Efe news agency.
The moment also belonged to Real Madrid coach Zinedine Zidane, who can point to a pair of Champions League trophies and a La Liga crown after just 18 months at the helm.
With his first goal, Ronaldo joined Alfredo Di Stefano as the only two players to score in three different European Cup/Champions League finals.
The second marker brought the four-time Ballon d'Or winner to 600 goals for club and country, including a record 105 in the Champions League.
To no one's surprise, the Portuguese striker was proclaimed the man of the match.
While many expected Real Madrid to prevail, few thought the score would be so lopsided, given that defensive-minded Juventus entered the final having conceded only three goals during their entire Champions League campaign.
Juventus, coming off their sixth consecutive Serie A championship and a triumph in the Coppa d'Italia, made the faster start in front of the more than 74,000 spectators at Cardiff's Millennium Stadium.
Eager to end their 21-year European title drought, Juve forced Blancos goalkeeper Keylor Navas to make two stops in the first four minutes.
Both occasions were created by Gonzalo Higuain, who first got his head to a Mario Mandzukic cross and then tested the keeper with a shot from distance.
Navas needed to be sharp again in the 6th minute to repel a low shot from Miralem Pjanic.
After surviving the early surge thanks to their keeper, Real Madrid began to find their footing.
The reigning champions took a 1-0 lead in the 20th minute as a result of a move that began with a rush on the counter by Toni Kroos.
Once in the offensive zone, Kroos passed to Karim Benzema and the Frenchman found Ronaldo, who worked a give-and-go with Dani Carvajal before posting his first goal of the night: a low shot that deflected off Juve defender Leonardo Bonucci and past keeper Gianluigi Buffon
The challengers responded, pulling level seven minutes later with a special goal by Mandzukic, who chested down Higuain's header and beat Navas with a breathtaking overhead volley.
Ronaldo had a golden opportunity in the 33rd minute to restore the Blancos' advantage, but his header was off-target and the sides went to the dressing rooms with the score knotted 1-1.
Zidane's half-time talk clearly did the trick, as Real Madrid dominated the second 45 minutes.
Blancos midfielder Casemiro neutralised Alex Sandro - a dynamo for Juve in the first half - and created space for Isco Alarcon and Luka Modric.
It was Modric who got the first chance after the restart, a strike from close range that Buffon managed to send wide.
But the go-ahead goal came in the 61st minute from Casemiro, who let loose from 30 yards out and benefited from a deflection off Juve's Sami Khedira.
Ronaldo delivered the fatal blow three minutes later, tucking the ball just inside the post with a major assist from Modric.
Juventus tried to battle back, but managed to create only a single chance in the ensuing 30 minutes and saw any hope of a comeback evaporate as Sandro's header off a Dani Alves free kick missed by inches.
The Italian club went down to 10 men with six minutes left, when substitute Juan Cuadrado was sent off for a second yellow card, and Marco Asensio made it 4-1 for the Blancos with a strike in injury time.