Juve coach Massimiliano Allegri rested several players ahead of next week’s Champions League last 16, return leg against visiting Atletico Madrid, which his side trail 2-0, including Mario Mandzukic, Cristiano Ronaldo and Paulo Dybala.
However, the Turin side had little trouble seeing off Udinese as they scored four goals for the first time this term and stretched their unbeaten league campaign to 27 matches.
Kean opened the scoring after 11 minutes when he stabbed in Alex Sandro’s cross from close range and doubled the lead five minutes before the break by prodding home at the near post.
At 19 years and eight days, the Italy international became the youngest player to score at least two goals in a Serie A game since 18-year-old Giuseppe Galderisi in February 1982.
Midway through the second half, Kean raced on to a long ball and was brought down inside the box by substitute Nicholas Opoku, and Emre Can sent the penalty into the corner.
Blaise Matuidi completed the rout in the 71st minute with a stooping header that bounced off the ground into the top corner, before Udinese substitute Kevin Lasagna got a consolation with a fine angled finish five minutes from time.
Juve have 75 points, having won 24 of their 27 matches this season and drawn the other three, while Udinese are 15th on 25 points ahead of the rest of the Serie A weekend programme.
Second-placed Napoli visit mid-table Sassuolo on Sunday.
(Reporting by Alasdair Mackenzie; Editing by Ken Ferris)
