#3 Real Madrid 4-2 Bayern Munich; 18 April, 2017 (Santiago Bernabeu, Madrid)
Cristiano Ronaldo almost single-handedly eliminated Bayern Munich from the 2016-17 Champions League quarter-final, as he scored five goals scored across both legs.
Remarkably, coming into the quarter-final, the normally prolific Portuguese had scored just two goals from eight games in the competition that season, leading many to write him off.
However, Cristiano Ronaldo is called 'Mr Champions League' for a reason, and he reminded everyone of his pedigree with a comprehensive display against the Bavarian giants.
A second-half brace in the first leg at the Allianz Arena helped cancel out a 25th-minute goal by Arturo Vidal to give Real Madrid the advantage on home soil.
Cristiano Ronaldo came to the fore again in the return fixture, scoring a header in the 76th minute to level matters after Robert Lewandowski had put Bayern Munich ahead.
With 14 minutes to go, Los Blancos were seemingly through to the semi-final, but a Sergio Ramos own goal two minutes later forced extra-time, and this was where the Real Madrid number 7 stood up to be counted.
The Portugal international controlled a Ramos cross on the chest before sliding a left-footed finish past Manuel Neuer, although replays showed him to be in an offside position.
Five minutes into the second half of extra-time, Cristiano Ronaldo was well-placed to finish an excellent counter-attack by Marcelo to complete what was a perfect hat-trick.
It saw him become the first player to score 100 Champions League goals and sent Real Madrid through to the semi-finals, which bring us to his next hat-trick in the competition that season.
#4 Real Madrid 3-0 Atletico Madrid; 2 May, 2017 (Santiago Bernabeu, Madrid)
Under the tutelage of the wily Diego Simeone, Atletico Madrid have earned the reputation of being one of the most compact football sides in history.
Nevertheless, Los Colchoneros must be sick of the sight of Cristiano Ronaldo, especially in the continent.
They had seen off debutants Leicester City in the quarte-rfinal of the 2016-17 campaign to book a date with their city rivals. The Rojiblancos would have had revenge in mind, following two final losses to Real Madrid in the previous three seasons, but that was not to.
Cristiano Ronaldo put the hosts ahead as early as the tenth minute with a header, rising above Stefan Savic to nod home a cross by Casemiro.
A defiant Atletico Madrid defence kept their hosts at bay, but two goals in the final 18 minutes from Cristiano Ronaldo condemned the Rojiblancos to a 3-0 defeat at the Bernabeu.
The hat-trick showcased the full range of Cristiano Ronaldo's abilities, with the player scoring a header, an 18-yard screamer and a poacher's finish to become the first player in Champions League history to score consecutive hat-tricks.
Another brace in the final against Juventus helped Real Madrid become the first team to successfully defend their Champions League title. But that may not have been possible had their talisman not scored the two hat-tricks in the two previous rounds of the competition.
#5 Portugal 3-1 Switzerland; 5 June, 2019 (Estadio do Dragao, Porto)
We are back to international football for another Cristiano Ronaldo hat-trick that inspired his nation to glory on home soil.
After sitting out the entire group-stage of the maiden UEFA Nations League, the Madeira native returned with a bang, scoring three goals in the semi-final to dispatch a talented Switzerland team.
The first of Cristiano Ronaldo's goals came in the 25th minute from a 25-yard freekick that dipped over the wall and left Yann Sommer stranded in his line.
Ricardo Rodriguez equalised for the Alpine nation in the 57th minute, and with just three minutes to go, it looked like the game would be decided in extra-time. However, Cristiano Ronaldo had other ideas, and he stamped his authority on the game with a brace in as many minutes to complete his hat-trick.
His second of the night saw him show his predatory striker's instincts, as he placed a one-touch finish from a Bernardo Silva cut-back to put his side 2-1 up.
The replays had barely finished playing when Cristiano Ronaldo got his seventh international hat-trick, recreating a scene which we have seen multiple times in the past but not recently.
In scenes reminiscent from his wing-wizard days at Manchester United, Cristiano Ronaldo received the ball out wide on the left, took a few touches, performed some step overs and left Manuel Akanji for dead before riflingll the ba into the far corner.
That killed off Switzerland, helping Portugal reach the final of the UEFA Nations League on home soil.
Goncalo Guedes settled the showpiece event against Netherlands at the hour-mark to help the Iberian nation to their second major international trophy. That might, however, not have been possible had Cristiano Ronaldo not stepped up to the plate three days earlier.