Ronaldo is chasing a number of European Championship records this summer, and he broke one of those against Czech Republic, having now featured in sixth European Championship finals.
The Al-Nassr forward had been level on five appearances with Spain legend Iker Casillas, but he has now moved out on his own, having featured against Czech Republic.
The 39-year-old, who played the full 90 minutes of his side's 2-1 win, has a number of other records to pursue at the tournament, including oldest player to score and most Golden Boot wins at the competition.
Ronaldo was also seemingly in line to become the oldest outfield player to take to the field at a European Championship, but his teammate Pepe has become the oldest player to feature in the tournament, having also been named in the starting side for Portugal's Euro 2024 opener.
Pepe, Ronaldo make history at Euro 2024
Indeed, Pepe featured against Czech Republic at the age of 41 years and 113 days old, breaking the record which had been held by Gabor Kiraly, who was 40 years and 86 days old when he turned out for Hungary against Belgium in the last-16 stage of Euro 2016.
Before Pepe and Ronaldo, the oldest outfield player to feature in the competition was German legend Lothar Matthaus, who was 39 years and 91 days old on his last appearance at Euro 2020.
There had been question marks over the futures of both Pepe and Ronaldo following the 2022 World Cup, but Portugal head coach Roberto Martinez immediately made it clear that the duo were still key players.
Pepe entered Euro 2024 off the back of making 35 appearances for Porto last season, while Ronaldo scored 44 goals and registered 13 assists in 46 appearances for Al-Nassr last term.
Martinez named a back three against Czech Republic, with Pepe operating alongside Ruben Dias and Nuno Mendes, while Ronaldo was joined by Rafael Leao and Bernardo Silva in the final third of the field.
Portugal are seen as among the favourites for Euro 2024
Francisco Conceicao scored a last-gasp winner to hand Portugal all three points in their Group F opener, with Czech Republic proving to be difficult opposition on Tuesday.
Portugal midfielder Bruno Fernandes also explained the importance of having Ronaldo and Pepe in the squad, as the national side bid to win a second European Championship title this summer.
"We all know it is important to have experienced players by our side," Fernandes told reporters after the match.
"Him and Pepe are probably the most experienced players in this tournament, not only in our team. We know they are big value for us and we know they are going to help us through the tournament."
As it stands, Jens Lehmann is the oldest player to feature in the final of a European Championship, with the former goalkeeper 38 years and 232 days old when he represented Germany against Spain at Euro 2008.