The lone goal from Valter Birsa proved to be enough for all three points, as Milan held the fort down at the back, keeping only their second clean sheet of the season.
Without further ado, here are five things we learned from this pivotal Serie A match.
Milan's young 21-year-old goalkeeper brought in from Cruzeiro last season might turn into a decent Serie A player.
With the club desperately needing a young quality goalkeeper to take over the reins from Christian Abbiati, Gabriel showed himself to be more than capable against Udinese.
This is a stark contrast from how shaky he sometimes looked during the preseason and during Brazil's Olympic tournament last year.
The man known as the "Maradona of Nova Gorica" struck again, this time with a fabulous long-distance shot that bent right into the top corner.
For an unheralded player who was a cast-off of Genoa, his summer signing came with little limelight when he was involved in the swap for Luca Antonini.
However, he's an energetic presence who can be a useful utility player and give Milan a different gear depending on the game situation.
With main strikers Mario Balotelli and Stephan El Shaarawy out due to injuries, it's worth noting that Milan are missing nearly half of their team either to suspension or those all-too-common knocks that have become a norm around Milanello lately.
El Shaarawy is due back in the first week of November, while Balotelli is questionable for the midweek match against Barcelona in the Champions League.
Massimiliano Allegri will now have the unenviable task of deciding which players will work best against Barcelona. For a team that has seemingly had a different starting lineup every game this season, it's hard to imagine that he even knows who his most trustworthy XI are.
With Matias Silvestre doing well, we might see a completely different pairing in January with Adil Rami coming into the mix alongside the Argentine defender.
Milan is Balotelli dependent, and there's nothing wrong with that.
When you have one of the premier young talents in world football who can shift the tide of a match with one moment of pure genius, it's fine to lean on his shoulders when you need help.
Balotelli picked up a thigh knock and was unavailable against Udinese. Now that those three points have been picked up, all eyes will turn toward the Barcelona match, where he is still listed as questionable.
Needless to say, Milan will go as far as Balotelli will take them in Europe.