Juventus is too far ahead on the scoreboard that Napoli is unlikely to threaten their position anytime soon.
Ancelotti says players played well but ultimately, the lack of scoring is unacceptable.
The Slovakian midfielder made his 520th appearance in Saturday's 3-0 win over Sampdoria.
The big guns suffered upsets with Juventus crashing 3-0 to Atalanta, Napoli falling 2-0 to AC Milan and Roma suffering a 7-1 humiliation at Fiorentina.
The match took place without incident apart from some anti-Neapolitan songs beforehand.
Carlo Ancelotti's side play an Italian league game against AC Milan this weekend before returning to the San Siro next Tuesday for a Coppa quarter-final showdown against Gennaro Gattuso's side.
Lazio are sixth, two points outside the top four places which earn a place in next season's Champions League.
Napoli, with 47 points, open up a 7-point gap between themselves and 3rd-placed Inter Milan.
Match officials in Italy are expected to report racist incidents to public security officials who have the power to stop games.
The incident occurred at the end of a fight between Napoli fans and Inter supporters armed with chains and hammers.
Kalidou Koulibaly was subjected to monkey noises from home supporters throughout the match.
The pressure is on Milan coach Gennaro Gattuso after Federico Chiesa's second-half scorcher pushed AC Milan out of the Champions League places.
Last year's runners-up Liverpool knew victory by two goals or a 1-0 triumph would put them through to the last 16 from Group C
Napoli, held 0-0 at home by bottom club Chievo in their previous game, took a second-minute lead when Fabian Ruiz turned in Lorenzo Insigne's cross.
Juventus moved on to 40 points, 11 ahead of second-placed Napoli.
Aided by a Davide Biraschi own goal, Napoli came from behind to beat Genoa 2-1.
The result sees Napoli go top of Group C, level on points with Liverpool following their shock 2-0 defeat by Red Star Belgrade earlier Tuesday.
The Italian goalkeeping legend says he is lucky to be able to return to Italy in a Champions League match.
Dries Mertens' hattrick led Napoli to a 5-1 win over Empoli.
When Napoli and Empoli face off in a Serie A match, both teams will probably exhibit playing characteristics instilled by former coach Maurizio Sarri.
According to coach Thomas Tuchel, Gianluigi Buffon will start for Paris Saint-Germain in games against Lille and Napoli.
Dries Mertens' late goal helped Napoli draw 1-1 against AS Roma.
Ángel Di María's goal gave PSG a 2-2 draw against Napoli.
Juve were all set to extend their fine run when Ronaldo put Massimiliano Allegri's men into a first-half lead.