However, the result may come at a cost for Juventus, who lost Paulo Dybala, Matthijs de Ligt, and Danilo to injury with just over two weeks remaining before they host Lyon in the second leg of their Champions League last-16 tie.
Ronaldo propelled Juventus into the lead in the seventh minute of first-half injury time when Miralem Pjanic feigned an attempt on net with his free-kick only to find the Portuguese talisman unmarked from 15 yards out.
The goal was Ronaldo's 31st in the league this season, putting the 35-year-old three adrift of Ciro Immobile in the Capocannoniere chase after the Lazio striker recorded a hat-trick during Sunday's 5-1 beatdown of Hellas Verona.
Sarri was forced to make two changes in the opening stanza. Danilo was taken off for Bernardeschi after colliding with Gaston Ramirez and suffering a head injury. Dybala was ushered off with what appeared to be a thigh issue and De Ligt compounded those concerns when he walked off favoring his leg 15 minutes before time.
The 2-0 scoreline on Sunday does a bit of a disservice to Claudio Ranieri's charges.
Sampdoria came close to equalizing four times early in the second half. Mehdi Leris missed an opportunity to level from close range before Ramirez's looping cross nearly snuck in at the far corner minutes later. Lorenzo Tonelli then headed wide off the ensuing corner and Ramirez directed a header of his own directly into Wojciech Szczesny's welcoming grasp a short time after that.
Bernardeschi all but secured the Old Lady's ninth successive title when Emil Audero batted a strike from Ronaldo directly into the path of the surging Italian attacker. The goal was Bernardeschi's first this season.
Sampdoria played the final 15 minutes down a man when Morten Thorsby picked up a second yellow for catching Pjanic with a rash challenge.
Ronaldo wasted a chance to make it 3-0 and draw a goal closer to Immobile when he thumped the crossbar from the penalty spot after Alex Sandro was scythed down in the area.
Sarri, 61, is now the oldest manager to win Serie A, with the former Napoli and Chelsea boss becoming the third tactician to lift the Scudetto with Juventus over the nine-season span.