Sassuolo led 2-1 through Jeremie Boga and Francesco Caputo before Ronaldo’s strike from 12 yards gave Juventus a glimmer of hope at the Allianz Stadium.
Juventus currently holds a two-point lead over Inter Milan, who host SPAL later today.
After a goalless opening quarter, Leonardo Bonucci broke the deadlock, rifling home from outside the box.
Sassuolo, however, were quick to respond, Boga dinking the ball over Buffon, following a give and go with Caputo.
After the break, Juventus came out with all guns blazing, only to give Caputo a goal with a terrible mixup and an error from Gigi Buffon.
Cristiano Ronaldo then equalised from the spot after Dybala was brought down inside the box by Romagna.
— JuventusFC (@juventusfcen) December 1, 2019
Juventus despite dropping points remains the only unbeaten team in the Serie A. The Bianconeri are on top with 36 points from 14 outings (11W 3D).
Inter Milan can go top, a point ahead of Juventus, with a win over SPAL.
Juventus will now travel to face third-placed, currently leading 1-0 at home against Udinese, next Sunday.
Serie A results
Brescia 0: Atalanta 3
Genoa 0: Torino 1
Fiorentina 0: Lecce 1