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.
The win moved Napoli three points behind leaders Inter Milan, who beat Udinese 2-1, while third-placed Atalanta lost 1-0 at Fiorentina.
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.
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.
Reigning champions Inter could cut the gap back to three points when they host Fiorentina on Monday.
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.
Georgia striker Khvicha Kvaratskhelia on Friday signed for Paris Saint-Germain for an undisclosed fee from Italian league leaders Napoli, the French champions announced.
Frank Anguissa and Amir Rrahmani scored Napoli's goals in an eight-minute spell in the first half before Andrea Pinamonti cut the deficit early in the second period.
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.
The win moved Napoli three points behind leaders Inter Milan, who beat Udinese 2-1, while third-placed Atalanta lost 1-0 at Fiorentina.
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.
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.
Reigning champions Inter could cut the gap back to three points when they host Fiorentina on Monday.
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.
Georgia striker Khvicha Kvaratskhelia on Friday signed for Paris Saint-Germain for an undisclosed fee from Italian league leaders Napoli, the French champions announced.
Frank Anguissa and Amir Rrahmani scored Napoli's goals in an eight-minute spell in the first half before Andrea Pinamonti cut the deficit early in the second period.
Fiorentina earlier remained on Napoli's heels after their 1-0 home win over Cagliari in their first league match since midfielder Edoardo Bove's sudden collapse last weekend.
