A Lewis Baker free-kick at the end of the first half gave the hosts the lead before goals after the interval from Jeremie Boga, Alex Kiwomya and between those two, a Baker strike from 35 yards settled the tie.
Blues coach Drummy told chelseafc.com: "You have to be really pleased to beat AC Milan. They were very complimentary before the game about the way we play so if that's getting around Europe then we're very happy. It's nice to receive those compliments from people like Filipo Inzaghi who've done great things in football."
For breaking stories and all the great banter like us on Facebook: facebook.com/tribalfootball