AC Milan are currently winning Napoli 2:0 right now and if the match happens to end like this then they will end this week and this month of September on top of the Serie A standings. So far this this season they have been good that is why they are now sharing the same point with Napoli if they win. It should be a win for them because they have a two goal advantage over their opponent as it stands now. Napoli will need to score twice without response for them to grab a point tonight.
Milan managed to by win 2-1 in the end even though they had to play the whole second half with 10 players. They had 0 goal attempts after the red card by the way. Allegri still brought 3 points somehow.

This was a bit unexpected win for me to be honest. I didn't wait for Napoli to lose points that easy. Hojlund had such a useless performance. If they had Lukaku maybe things might have been different. Now Milan are the new leader in the Serie A.
After the 2-1 score and Milan red card, Napoli launched a devastating attack, nearly overwhelming the Milan defense. Fortunately they held on until the final minutes and secured three points, even with only 10 men.
I agree that Lukaku role is irreplaceable, and Hojlund hasn't been enough to sharpen the attacking line. The top five positions are still very volatile, as the margins are slim, and they could still change if each team can't maintain their consistency.
I believe that Lukaku is a key player and has always been, it's incredible how people can think that he is easily replaceable, that boy is a real goalscorer and it's certainly not a few games that will make Conte forget about him, they realized it now by facing a team that is doing well and that is sorely lacking in front of goal