The 22-year-old striker scored both goals in the Rossoneri's 2-1 victory over Udinese at the San Siro in Serie A.
"He is a big-time player and he started after [Giampaolo] Pazzini got injured; football is strange," Galliani told Milan's official website.
"Balotelli's two goals were a sign of fate and he could have scored after 35 seconds. I didn't see the second goal because I was in the dressing room. "
"President [Silvio] Berlusconi spoke to the players and was very pleased," he said. "Our attack has a combined age of 60 and for the next 10 years I can rest easy. We have picked up 33 points in the last 15 games.
"We don't have [Lionel] Messi but we have Balotelli. This attack reminds me of Barcelona and we will see the benefit in terms of sponsors because he is only 22 and he has great potential."
Milan are currently fourth in Serie A with 40 points from 23 matches.