The 33-year-old rifled a swerving shot into the top left corner to complete both his 16-minute double and Juve's recovery in the testing 2-1 victory.
His first was a coolly-taken penalty that cancelled out Francesco Caputo's classy 28th-minute opener as the champions relied on their star forward to temporarily move seven points clear in Serie A.
"It was a tough game. We knew it would be complicated, even the coach anticipated it, but we gave a good answer," Ronaldo told Sky Sport Italia
"In the second half we pushed more, created opportunities and deserved the victory.
"I don't remember my goal very well, I'll have to watch it again! It happened very quickly. I was confident and went for it.
"This was an important week, the team was tired after Manchester, and we did well in difficult circumstances."
Ronaldo's decisive 70th-minute strike helped Juve avoid what would have been a second straight Serie A draw and earned him fresh plaudits from Massimiliano Allegri.
"We won thanks to the feat of an extraordinary player," the Bianconeri boss said.
"I hope they show the goal to kids so they try to imitate it. Children need more practice than theory."