Ronaldo scored a stunning header to give Real a 1-1 draw at the Bernabeu but, despite the importance of the last-16 clash, he declined to celebrate against his former employers.
The 28-year-old's allegiance is not in question and he remains confident the Primera Liga side can progress, but he was keen to show United his respect after cancelling out Danny Welbeck's goal.
"I didn't see the replay of my goal but I will. They told me it was a beautiful goal," he told The Sun newspaper.
"I didn't celebrate the goal because Old Trafford is a home where I played for six years, and I arrived there almost as a kid.
"It's not about not celebrating. I want to win but I respect the people of Manchester.
"It was beautiful and emotional to play against my family.
"If I left Madrid for another team one day, I would not celebrate against Real."
An away goal means United have a marginally better position heading into the return leg on March 5, but Ronaldo is unconcerned about the challenge in front of Jose Mourinho's men.
"We created but did not finish off our chances, and this is wide open for the return match.
"We go there to score goals and go through. No big deal.
"We shouldn't change the plan we have because we always have the initiative and we will try to win at Old Trafford.
"This 1-1 is not perfect but it's a good result."