The result was not easy to come by for Juve, with returning goalkeeper Gianluigi Buffon saving an early penalty, but goals from Adrien Rabiot, Ronaldo and Paulo Dybala meant they stayed fifth, two points off the Champions League qualification places.
Buffon, who announced this week that he is leaving the club at the end of the season, replaced Wojciech Szczesny in goal and immediately showed he has lost none of his ability as he brilliantly kept out Domenico Berardi's spot kick.
The chances kept coming and going for the home side, and their profligacy proved costly as Rabiot drilled home the opener in the 28th minute, before Ronaldo reached another goal landmark just before the break.
Sassuolo continued to do everything but score, until Giacomo Raspadori did finally beat Buffon just before the hour mark.
But Dybala also reached a century of Juve goals, with a fine finish six minutes later to ensure they kept pace with their top-four rivals Atalanta, AC Milan and Napoli, who all won in the latest round of matches, with two games to play.
But for Juve, with the pressure mounting on coach Andrea Pirlo after a meek surrender in a 3-0 loss to Milan at the weekend, it was imperative they did not drop more points.
"It was important to win tonight, we were so poor in the match with Milan," Rabiot told DAZN. "We wanted to do more, we suffered but the attitude was the right one.
"We are all angry, Juve must do better. We must try to win the last two games and see what happens."