Milan moved five points clear at the Serie A summit with a 1-0 win over Empoli, as Pierre Kalulu's stunner settled a cagey match at San Siro.
French defender Kalulu netted a superb first-half opener for the Rossoneri, who restricted Empoli to just one shot in the first 45 minutes during a dominant showing.
Although the visitors improved after the break, they struggled to create clear-cut chances against the title challengers, as Milan took an important three points from a tight affair.
The result gave Stefano Pioli's men breathing space at the top of Serie A, while Empoli remain without a win in 2022.
Milan were denied an early lead when Guglielmo Vicario saved well from Alessandro Florenzi's curling effort, and they again went close when the ball ricocheted off Sandro Tonali and rolled wide.
But the hosts did hit the front on 19 minutes when Kalulu finished brilliantly from the edge of the area, firing home with his left instep after the ball deflected to him.
However, Mike Maignan was forced into two stops within five minutes of the restart, turning Sebastiano Luperto's header around the post before punching Nedim Bajrami's goal-bound corner away.
Two tame Junior Messias shots, both drawing routine saves from Vicario, were the sum of Milan's efforts for much of a dull second half in which chances were at a premium.
However, Milan's solid defensive display was enough to hand them the victory and strengthen their position in one of Europe's closest title races.
What does it mean? Rossoneri claim vital win in Scudetto hunt
With rivals Inter travelling to Torino on Sunday, Milan have, at least for the time being, established a five-point lead at the top of Serie A.
The Rossoneri are now unbeaten in seven league games, earning four wins and three draws, as they hit form at the ideal time in the hunt for a first league title since 2011.
They must now hope Inter drop points in their two games in hand.
Landmark goal for coach Pioli
Kalulu's fantastic opener was his first goal of the season and was also a landmark moment for Milan boss Pioli.
The 56-year-old, who is looking for the first league title of his career, became just the seventh coach to see his teams score 600 Serie A goals in the three-points-for-a-win era.
Milan improve record against strugglers
Milan's title challenge has, at times, been held back by an inability to beat lowly opponents in Serie A. This win represented just their third victory in their past seven games against bottom-half teams.
Meanwhile, the result represented a third successive win for the Rossoneri against Empoli, after they only won two of the previous seven head-to-head meetings (four draws and one defeat).
What's next?
The Rossoneri's next Serie A fixture takes them to Cagliari in a week's time, while Empoli will host Verona in league action the following day.