Milan were held to a goalless draw after a wasteful display meant the champions picked up just a point away at winless Cremonese in Serie A on Tuesday.
Stefano Pioli's side dominated the first half, though a magnificent performance from Cremonese goalkeeper Marco Carnesecchi kept out efforts from Divock Origi and Junior Messias.
Origi saw a goal disallowed in the second half and despite some late pressure, the hosts clung on to pick up just their seventh point of the season.
Milan cut Napoli's lead at the top to eight points, but just a draw against such a lowly side will be frustrating for Pioli's men as they lose pace on the table-toppers.
The Rossoneri controlled possession early on, but struggled to create anything clear-cut until Brahim Diaz poked Messias' cross wide after 23 minutes.
They had an even better chance soon after when Origi was slipped through on goal by Ante Rebic, though the former Liverpool striker's low shot was saved by Carnesecchi.
More impressive work from Carnesecchi was required soon after, first diving to his right to palm away Malick Thiaw's header from a corner, before a smart stop to deny Messias ensured Cremonese made it to the break level.
Origi thought he had broken the Cremonese resistance 11 minutes into the second half, but his sliding finish was ruled out by VAR after he was adjudged to be offside.
Rafael Leao was then thwarted by Carnesecchi as Milan pressed for a winner, but they could not find one as they were forced to settle for a point.
What does it mean? Milan miss chance to keep up with Napoli
Milan could and should have won this game, but their inability to do so means they lose pace on Napoli in their bid to retain the title.
Pioli's side registered 16 shots to Cremonese's six, but mustered just 0.95 xG (expected goals) as they lacked the cutting edge needed to break down the hosts' defence.
Carnesecchi the saviour
Even when Milan did get through the sturdy Cremonese backline, Carnesecchi was on hand to keep them out.
The 22-year-old goalkeeper, on loan from Atalanta, made five saves to help his team to an impressive draw, which sees them move two points from safety.
Origi off the boil
With Olivier Giroud suspended after receiving a second yellow for his post-winner celebration against Spezia, it fell upon Origi to lead the line against Cremonese.
The Belgian failed to get himself on the scoresheet though as Milan drew a blank, missing a great chance when one-on-one in the first half before his would-be winner was ruled out by VAR. With the visitors needing a goal, Origi was then taken off with half an hour still to play.
Key Opta facts
- Milan have failed to win two of their last four games against newly promoted sides in Serie A (D2), having won 10 of their previous 11 such matches (L1).
- The Rossoneri have failed to win four of their seven away games in Serie A this term (D3 L1); in the entire 2021-22 season, they only failed to win five games on the road (D4 L1).
- Cremonese remain one of the two teams, alongside Elche, yet to win a single game in Europe's top five leagues in 2022-23.
- This was Sandro Tonali's 100th game for Milan in all competitions, and Simon Kjaer's 150th match in Serie A.
- Marko Lazetic became the first player born in 2004 to play a game in Serie A for Milan.
Cremonese will travel to play Empoli on Friday, while Milan host Fiorentina on Sunday before the teams pause for the World Cup.