The mercurial Swede got both goals in a 2-0 win for Stefano Pioli’s side at San Siro, scoring a towering header from Theo Hernandez’s first-half cross before doubling his tally from the penalty spot after the break.
He looked certain to seal his hat-trick midway through the second half after taking the ball around goalkeeper Lukasz Skorupski, but blazed over with the goal gaping - missing the opportunity to become the oldest-ever player to net a triple in Serie A.
"I'm fine, I'm working, this is the second official match,” Ibrahimovic told Sky Sport Italia after the game.
“We won, I could have scored more goals. If I was 20, I would have scored another two. I'm like Benjamin Button, I was born old and I die young.”
Milan have started the season positively, with Monday's result following a 2-0 away win at Shamrock Rovers in Europa League qualifying.
They will be hoping to carry on their superb form from the end of last season, when they rose to sixth in the table with nine wins and three draws from their final 12 league games.
Ibrahimovic was crucial to that run, scoring 10 and assisting five in 18 Serie A appearances after his move from LA Galaxy.
"We are not yet at 100 per cent, we still made some mistakes that we usually wouldn’t,” he added.
“Today it was important to win the first game and start well. Our goal is to do better than last year.
“The young players are doing well; they work, they listen, they have discipline, they know that you have to suffer, work and be focused every day.
"This year we have to think one game at a time and do well, play confidently and play every game like a final. The goal is to stay high in the table.
“I like to have responsibility. The biggest pressure comes from myself. I don't want anyone to talk about my age, I want everyone to be judged on the same level - I don't want any favours because I'm 38.”