0324 GMT January 20, 2020
Leonardo Bonucci had scored early for the eight-time reigning Serie A champion but Jeremie Boga and Francesco Caputo hit back for Sassuolo before Ronaldo's point-saving intervention, AFP reported.
Juventus has accumulated 36 points from 14 matches.
Sassuolo claimed its first ever point at Juventus and handed Maurizio Sarri's unbeaten champion its third draw of the season.
The side from Emilia-Romagna has notched up 14 point from 13 matches.
Ronaldo started up front for Juventus, having missed last weekend's league game with a slight knee problem, with Champions League hero Paulo Dybala starting on the bench.
Eighteen-year-old Stefano Turati made an impressive debut in the Sassuolo goal, and pulled off a string of fine saves, denying Ronaldo, Higuain and Dybala late.
But Juventus counterpart Gianluigi Buffon had a difficult game in Turin as the 41-year-old, making just his fifth start this season, had a role in Caputo's goal just after the break.
Bonucci had gotten Juventus off the mark with a long-range effort on 20 minutes.
But three minutes later Boga pounced on a Caputo cross sending in past an out-rushing Buffon from an angle.
Back after the break Caputo added a second for the visitor following a mix-up between Juan Cuadrado and Matthijs De Ligt in the Juventus defense, with Buffon then fumbling the effort as it slipped into the back of the net.
Turati got down low to deny Higuain after getting his hand to send a Ronaldo free kick over the bar.
Ronaldo's penalty pulled the host level on 68 minutes after Filippo Romagna fouled substitute Dybala.
It was the Portuguese star's fifth Serie A goal this season.