The 39-year-old hooked in a seventh goal in just four league appearances this season.
“Mine was a good goal but the victory counts more,” said Ibrahimovic.
“We are among the youngest teams in Europe, I take the blame for raising the average age, but they all make me feel younger.”
Ibrahimovic – who now has 17 goals in 22 Serie A games in his second spell with Milan – created the first goal for Franck Kessie before Rodrigo de Paul pulled Udinese level from the penalty spot.
Ibrahimovic snatched the win when he acrobatically beat Udinese defenders Rodrigo Becao and Sebastian de Maio to beat goalkeeper Juan Musso with a close-range overhead kick.
Milan are unbeaten in 24 matches since competition resumed in June after the coronavirus lockdown.