The Rossoneri midfielder was thrilled with his compatriot's display after he came off the bench to score two second-half goals in three minutes to seal victory over Catania
Pazzini came off the bench in the second half to score two goals in three minutes before Mario Balotelli sealed the points with a late penalty and Montolivo was thrilled to see his compatriot perform so well when it mattered most to the side.
"This was a big result for us and we always believed we could do it," the 28-year-old told Milan Channel.
"Pazzini coming on certainly helped to change things for us. When he came on, it gave us a massive lift. You have to say that he was really decisive. I'm really pleased for him.
"We did everything we could to win. We showed heart, and everyone gave their all from the first minute. We put our foot on the gas from the start.
"We wanted to score, and we created plenty of chances. We came close to scoring, but the ball would not go in, and then the first free kick we gave away, we conceded a goal.
"It wasn't easy in terms of how we had to approach the game after that, but we did well and we kept calm, and it went our way in the end."
The win propelled Milan back into third place above Fiorentina, who are running the Rossoneri close for the final Champions League qualification spot.