The Portuguese athlete then scored a second goal for the Italian champions, following his record €112 million move from Real Madrid during the summer transfer period.
The first goal came after a goalmouth scramble on 50 minutes, and the second followed 15 minutes later to give Juventus a 2-0 lead.
The match ended with Juventus defeating Sassuolo 2-1 and maintaining their perfect start to the season.
Ronaldo was visibly relieved to score his first goal for Juventus, as he sprinted to the corner flag and leaped into the air in front of cheering fans.
His teammates were quick to run over and embrace him.
It took the five-time Ballon d’Or winner almost 320 minutes to score his first goal for the side.
“I wanted to score, I’m really happy,” Ronaldo said after the game.
“Certainly there was a bit of pressure in general after my move from Real, there was a lot of expectation.
“My teammates are helping me hugely to adapt to this new league.”
Juventus coach Massimiliano Allegri had said the day before the match he was not worried that Ronaldo had failed score despite 23 shots at goal since the beginning of the season.
“I don’t expect Ronaldo to do more or less than what he did in the first three games,” he said.
“I believe tomorrow could be his day.”
Allegri was right about the 33-year-old, who scored 44 goals for Real Madrid last season including 15 in the Champions League on the way to a third straight title.
Juventus is seeking a record-extending eighth consecutive Serie A title.
