Juventus settled for a stalemate against Udinese after a brilliant two-goal lead in the first half.
Paulo Dybala opened the scoring in the third minute after which Cuadrado netted a second with a low drive twenty minutes later.
However, Juventus’ joy was short-lived as the hosts managed to equalize before the 84th minute.
Ronaldo, 36, replaced Alvaro Morata on 60 minutes and thought he had headed in an injury-time winner, only for the goal to be ruled out by VAR.
He was also booked for removing his shirt during the celebration.
Returning boss Allegri chose Morata to lead the line in a front three that also included Paulo Dybala and Juan Cuadrado, who were both on target.
Roberto Pereyra pulled a goal back with a penalty against his former club after goalkeeper Wojciech Szczesny’s clumsy lunge on Tolgay Arslan.
The hosts equalised in dramatic fashion as former Everton and Watford winger Gerard Deulofeu’s 83rd-minute strike stood after VAR overturned the on-field decision that had ruled it out.
