#3 Mentality

It's evident, Atletico Madrid are old victims of Cristiano Ronaldo. After that first goal, they were pushed onto the back foot and never looked to get the job done despite leading for the most part over two legs. As the match went on, it was crystal clear that whatever game plan Atletico had, it went out the window.
Meanwhile, Cristiano is accustomed to pressure. He has scored hat-tricks before and helped his teams score three goals to mount a comeback, most notably against Wolfsburg. He was hungry and determined to make his mark and help his team qualify, and he did just that.
Whereas Juventus previously faltered despite scoring three goals at the Santiago Bernabeu, it is obvious that Cristiano's arrival bolstered their chances, and made them more confident of securing a comeback.