On this day in 2017, Ronaldo became the first-ever player to score 100 European Cup/Champions League goals after netting his first and only "perfect" hat-trick in the competition (headed, right and left-footed vs FC Bayern).
In that match, Real Madrid beat Bayern 4-2 in their second-legged clash in the semi-finals. Ronaldo scored a perfect hat-trick, including 2 goals in the extra time. Los Blancos eliminated Bayern with an aggregate score of 6-3.
Real Madrid finally beat Juventus to claim the trophy. That was their third UCL trophy in the last 4 years.