The Portuguese sensation scored twice within three minutes against title rivals Lazio to put Juventus on the cusp of yet another league title.
Ronaldo converted a penalty after VAR determined a handball, then finished off a swift counter attack following a pass from Paulo Dybala in the 2-1 victory.
The brace took him to 51 Serie A goals in total but he became the quickest to reach half a century, doing so in just 61 league games.
Former AC Milan striker Andriy Shevchenko previously held the record by getting to 50 goals in 68 games, while Brazilian Ronaldo reached the 50 mark in 70 appearances.
Sarri heaped praise on his talisman after the full-time whistle, insisting his poaching instincts are still as sharp as ever.
“When Cristiano smells blood… He’s extraordinary, as he recovers so quickly between games,’ the former Chelsea boss told Sky Sport Italia.
“It’s not just physical, but psychological.
“He could be someone who uses up so much energy in each game, but he recovers it every time and he’s world class in the mind as well as the legs.”
By scoring twice, Ronaldo also became the first player to score at least 50 goals in the Premier League, LaLiga and Serie A.
His 51 in Italy go alongside his 84 in the Premier League, and 311 in LaLiga and he played down his achievement after the game.
“Records are always important, but the most important thing is that the team wins,” Ronaldo said.
“We are a phenomenal team and we showed that again today, although we always want to improve and raise the bar.”
Juventus earned a measure of revenge after losing twice to Lazio in December – in Serie A and the Italian Super Cup.
Ciro Immobile pulled one back for Lazio with a penalty in the 83rd minute and the Italian and Ronaldo are now level in the top scorer standings with 30 each.
