Ronaldo’s double ensured the Italian champions would not lose to their rivals for a third time this season.
It also meant the Turin club could clinch a ninth consecutive title this week.
With four rounds remaining, Juventus moved eight points clear of Inter Milan, nine ahead of Atalanta, and 11 in front of Lazio.
Ronaldo converted a penalty after the VAR adjudged a handball, then finished off a counter-attack following a square ball from Paulo Dybala.
In doing so, Ronaldo became the first player to score at least 50 goals in the Premier League, LaLiga and Serie A.
His 51 in Italy go with his 84 in the Premier League, and 311 in LaLiga
“Records are always important, but the most important thing is that the team wins,’ Ronaldo said afterwards.
