Sergio Conceicao has backed Rafael Leao to "become the best in the world" after his impressive impact off the bench helped AC Milan triumph in the Supercoppa Italiana.

The winger came on early in the second half, shortly after Inter's second goal, helping Milan turn the game around, including getting the assist for Tammy Abraham's 93rd-minute winner in their 3-2 victory.

Leao also won the free-kick from which Theo Hernandez curled in a delightful strike from 20 yards before being involved in the build-up for Christian Pulisic's equaliser.

The 25-year-old created two chances in the match, getting an assist from one of those, while he also had the second-best passing accuracy in the final third (88.9%) of players to make more than three such passes.

Leao was not fully fit going into the match, but Conceicao was delighted with the impact his substitute provided.

"Leao is phenomenal. I've known him for a long time. He is Portuguese like me, but he is more relaxed Portuguese, and I am more tense," Conceicao said.

"He needs to learn a few things, and then I believe he can become the best player in the world. I've told him this too. He has so much individual quality, and if he puts it to the service of the team, he can be even better.

"I have no doubts he can become the best in the world next season if he learns those things."

Milan secured their eighth Supercoppa Italiana, moving level with Inter, while they also secured back-to-back victories over the Nerazzurri for the first time since a run of three straight wins between November 2010 and August 2011.