The coach was unequivocal in his praise for the captain, claiming there are still big margins for improvement from the Nerazzurri
The Nerazzurri boss handed Zanetti his first appearance since April, watching in satisfaction as the 40-year-old made an immediate impact in the build-up to Yuto Nagatomo's goal.
With the captain's successful battle against Achilles tendon surgery now complete, Mazzarri was quick to remind the squad that they should continuously look up to the Argentine for inspiration.
"All our players have a lot to learn from Zanetti, just by looking at him and seeing that you can make a difference," the coach told reporters.
"Lots of things come to mind but it would probably sound like adulation. I said what I think in the dressing-room. He's world class and you saw that today.
"In just 10 minutes when he came on he was a calming presence for the whole team. You don't find many people who can slot back in with so much ease after an injury like he had."
Scudetto rivals Juventus and Napoli clash on Sunday, but Mazzarri insisted he had no time for matters beyond those of training his team, which he harboured high expectations of.
"Believe me, I'm not looking at the others in the slightest. I'm busy making sure my own players keep improving, people like [Saphir] Taider and [Mateo] Kovacic," he continued.
"Mateo is very young. He has to learn to more pragmatic and that will come with time - he's a smart lad. Ricky [Alvarez] wasn't at his best today but he and [Fredy] Guarin were still getting into spaces.
"They're very talented lads and they still have a big margin for improvement."
Mazzarri was brought in to revive the San Siro outfit after a ninth-place finish last term, and has sparked a turnaround in their fortunes this season.