Boateng had been out for over two months with a hernia.
"I am very happy for my return on the pitch," he told the Milan Channel. "These three points are very important.
"Now we have two days to rest and prepare for the match with Napoli.
"We are happy that Alexandre Pato scored. The fans were very important for us.
"We called them, because we felt that we needed their support and they gave it to us."