This match is most likely to be a draw. Both the teams are equal in points, and both the teams are performing quite well this season. No one wants to lose their position in the points table by losing points. But I think the team that wins this match will be at the top of the points table for some time.
In the Champions League too, the Napoli team has won well against Liverpool and Rangers. Napoli dominated both matches. AC Milan's performance on the other hand has been very consistent. However, this match may be played by both teams in a defensive strategy. A 1-1 goal could lead to a draw. I will bet on a 1-1 draw.
Napoli vs Milan is a big clash in Serie A and they both have good form in first few matches. Again Napoli began a season very well just similar to the last one. They surprisingly replaced Insigne and Koulibaly very successfully. This clash is a big test for Napoli not only because if they can not win, other clubs behind can take over their position on the standing table. It is also because a win against AC Milan will boost the mentality of Napoli to a higher high.
Inter Milan will travel to Udinese headquarters, and this is clearly a real threat to Inter Milan. We know Udinese are in a positive trend and they can even beat AS Roma without reply. When compared to Inter Milan, indeed Inter have better players, but they did not work well in the game, several times they had to slip and accept defeat.
Don't forget that Udinese just had a big won against AS Roma recently. They are not an easy opponent to cope with and Inter Milan have to pay more attention because they will be hosted by Udinese. Oppositely, Inter Milan did not have too good form in early of the season and this brings more hope for Udinese to at least get a point from Inter.