This time around, the Rossoneri managed an important 1-1 tie against the Spanish giants at the San Siro, picking up a precious point and keeping them second place in their group.
With the lone Milan goal coming from a wonderful early game interchange between the two Brazilians Kaká and Robinho, it was Barcelona that would fight back with Lionel Messi scoring after a disastrous defensive sequence from the home team.
Without further ado, here are five things we learned from this Champions League encounter:
It's unclear whether or not they were feeding him tranquilizers in Madrid, but the Kaka we saw against Barcelona had many shades of the one Milanisti fell in love with years ago.
He was the key component behind Robinho's first goal, when he slipped in a lovely ball right into the path of the streaking Brazilian. Other than that, he was asked to play on the left of Allegri's 4-3-3, with more defensive duties than he has ever had.
Kaka showed the coach that his heart still bleeds red and black, tracking back to help the defense against the rabid Barcelona offense.
Milan director Adriano Galliani said after the match that he won't be able to sleep at night because of that woeful Robinho control where he basically let the ball slide right under his legs in what was perhaps the best scoring opportunity of the night.
Instead of giving his team a chance to mount another lead, Robinho showed exactly why he has always been an underachieving disappointment.
Massimiliano Allegri is bringing back the 4-3-3 under recommendations from both Galliani and President Silvio Berlusconi.
With Kaka playing the Stephan El Shaarawy role and Robinho as a false No.9, Milan looked dangerous up front especially in the first half.
If this type of rhythm continues, expect the Rossoneri to mount another comeback domestically like they did last season.
Barcelona has had a tough time away from home against Italian opposition, and this match didn't do anything to dispel the theory.
Even though they're one of the most dangerous teams in the world, they seem to lack innovation up front when faced against a side that's a bit more tactically sound.
Milan did a good job in doubling up on the flanks with both their wingers helping out defensively, which helped somewhat in stopping Barcelona players getting behind the back four.
It's a tired cliche at this point but one that still rings true—Milan has the Champions League in their DNA.
With a sold-out San Siro setting the stage, Milan gave spectators a reason for hope as they went head-to-head with one of the true giants of Europe.
It helped that Massimiliano Allegri fielded players with valuable Champions League experience like Kaka and De Jong, and had a game plan which worked in keeping a low scoreline.
Going forward, expect this team to show another gear assuming they get past the group stages, which at this point is Milan's to squander.