The 33-year-old scored what turned out to be the winner four minutes into the Group B encounter at the Luzhniki Stadium to put the Euro 2016 champions on the verge of the knockout stages.
Ronaldo's 85th goal for his country means that the Real Madrid star has now scored more international goals than any other European player in history.
"I'm very happy," Ronaldo told reporters at full time. "The most important [thing] was to win the game. To get the three points. Because if we lost we could be out. So, we knew that Morocco would be trying very hard.
"It was a surprise because at the start they were really going through a lot of moves and they were very strong. And we managed to score a goal, I managed to score a goal, to get those three points, so I'm very happy. And it was beautiful to me."