Juventus conceded their place in Serie A's Champions League positions on Wednesday after falling to a 1-0 defeat at Parma, one of four matches rescheduled from Monday following the death of Pope Francis.
The Italian football federation (FIGC) announced that all games across professional and amateur football on Monday would be rescheduled to a later date.
Inter Milan are level with Napoli at the top of Serie A after Riccardo Orsolini fired Bologna to a last-gasp 1-0 win over the reigning champions on Sunday.
Scotland midfielder McTominay nodded home his 10th goal in all competitions this season from Giacomo Raspadori's cross in the 72nd minute to save Napoli's blushes after a drab display in northern Italy.
Belgium striker Lukaku has scored 12 times and set up 10 more in Italy's top flight this season and has been key to Napoli's battle with reigning champions Inter for the league title.
"We've had a lot of commitments, we'd just played a derby, and you can't always find the right spirit to get the three points," said Inter's assistant coach Massimiliano Farris to DAZN.
Inter Milan and AC Milan's Italian Cup semi-final was left finely balanced on Wednesday after the two giants of Italian football played out a 1-1 draw at the San Siro.
Inter Milan and AC Milan's Italian Cup semi-final was left finely balanced on Wednesday after the two giants of Italian football played out a 1-1 draw at the San Siro.
The win moved Napoli three points behind leaders Inter Milan, who beat Udinese 2-1, while third-placed Atalanta lost 1-0 at Fiorentina.
The Italian Super Cup, which is played between the winners and the runners-up of the previous season's Serie A and Coppa Italia, was hosted in Saudi Arabia in January where AC Milan defeated Inter Milan 3-2 to win the trophy for the eighth time.
Antonio Conte's side are level on 61 points with reigning champions Inter after a largely lacklustre performance which with better finishing would have still been enough for victory on the Venetian Lagoon.
Netherlands midfielder Reijnders struck in the 76th minute after a brilliant Tammy Abraham pass as Milan came from behind to placate angry home fans and move up to seventh in Italy's top flight.
Antonio Conte's Napoli climbed back to within a point of leaders Inter Milan, who came from two goals down to beat bottom side Monza 3-2 on Saturday.
Lautaro Martinez proved decisive in the 77th minute to serve up his team's victory with a header slightly deflected into goal by Monza's Greek defender Giorgos Kyriakopoulos
Argentina striker Martinez's deflected header from a corner in the 78th minute was enough for champions Inter to get past revitalised Genoa and move a point above Napoli, who are at Como in Sunday's early kick-off.
Francisco Conceicao made sure that Napoli would stay two points ahead of reigning champions Inter by classily tucking home the winning goal 16 minutes before the end of an entertaining contest in Turin.
Reigning champions Inter could cut the gap back to three points when they host Fiorentina on Monday.
Udinese fans ambushed a train carrying rivals from Venezia after their Serie A match Saturday, triggering a massive brawl that left several injured and caused eight arrests, Italian police said Sunday.
Belgium striker Lukaku nodded home his eighth Napoli goal from Andre-Frank Zambo Anguissa's perfect cross in the 78th minute to give Antonio Conte's team a statement win in Bergamo.
