Heading into the game, both sides were on 4 points and needed a positive result to increase their chances of progressing further.
In the reverse fixture at Stamford Bridge, the Blues battered the Rossoneri 3-0, who were gunning for revenge in Milan.
The Italian champions also earned a big boost as Theo Hernandez was fit to participate, his absence at the Bridge was gravely felt by Milan.
The teams walked out to a packed San Siro, clamorous as usual, and it looked like we had a proper contest on our hands.
Unfortunately, the game ended up being far from even, with Chelsea eventually winning 2-0.
Goals from Jorginho and Pierre-Emerick Aubameyang settled the tie, as the Blues earned the top spot in Group E.
What looked like a contest at first turned on its head after a controversial decision from the referee.
Mason Mount got on the end of a through ball from Reece James and ran towards the goal, with Fikayo Tomori on his trail.
The former Chelsea player clawed at Mount’s shoulder and ended up bringing him down inches away from the goal.
The ref quickly arrived on the scene, handed Chelsea a penalty and controversially, gave Tomori his marching orders.
Up-stepped Jorginho, who is known to be lethal from the spot.
The Italian ended up marking his 200th appearance in Blue with a goal, as he calmly slotted the ball home. He employed the hop and skip, and once again, it delivered.
A penalty may look a simple affair on television sets, but on the field and under pressure, it’s truly a tall order. And as it turns out, Jorginho was dealing with another obstacle.
After the game, images surfaced online that displayed lasers being pointed straight into the eyes of the Italian.
It’s a simple yet effective technique to misdirect the taker and has worked to fruition on many occasions, including Mo Salah’s infamous pen for Egypt.
But nothing could deter Chelsea’s regista on the night, as he was ice cold from the spot as ever.
The goal and sending-off swayed the game in Chelsea’s favour, capping off a solid all-around performance for the Italian.
Another win will likely secure the London outfit’s progression in the tournament, while Milan will need straight wins and a bit of help from lady luck.