Two goals from Cristiano Ronaldo, one from Casemiro and one from Marco Asensio were enough to get Real Madrid a back-to-back UEFA Champions League win in Cardiff.
Ronaldo open the goal in the 20th minutes before Mandzukic leveled up in the 27th minutes for Juventus after an overhead superb kick.
Casemiro scored the third goal in the 60th minutes before Marco Asencio netted the final goal in the 90th minutes.
Zidane has now won back-to-back Champions Leagues – as well as this season’s La Liga title – since he took charge of Real in January 2016.
Italian champions Juventus have lost five Champions League finals since they last won the competition in 1996.
Real forward Gareth Bale came on as a 77th-minute substitute in his home city after recovering from a calf injury
Real Madrid now sets a record by winning the trophy back to back.