The leaders lose the unbeaten run of 'Maradona'.
Maurizio Sarri's Lazio, a former player booed by Napoli fans, accomplished the feat thanks to a somewhat casual goal by Vecino in the middle of the second half, at the end of a not good match and even boring for long stretches.
Those who expected a fun and sparkling football from the confrontation between Spalletti's and Sarri's teams are disappointed.
Exaggerated tactics are the leitmotif of a race which, if it hadn't been for a random episode, would have disappointed expectations even more.
The match is extremely tactical with the teams led by two coaches who impose movements on their players in such a radical way, without leaving any room for imagination, as to determine a race that is boring for long stretches, which is consumed in repeated tackles,
especially in midfield, which never lead to dangerous actions.
The tactical difference between the rivals consists only in the attitude of the defenses with Napoli which presides over its own penalty area and waits for the opponents and with Lazio which, at the start of the opponent's action, as per the custom of the teams coached by Sarri, pushes the four defenders up to the midfield line.
However, this attitude of the Biancocelesti fully achieves the goal of preventing Osimhen's holes and Lozano and Kvaraskhelia's lateral strikes because the three Napoli forwards, having to systematically retreat to avoid ending up in offside, never find the necessary space to enter the speed in the shirts of the Lazio defense.
Only one goal chance is produced during the first half of the game.
In the 5th minute Vecino extends the trajectory of a free-kick kicked by Luis Alberto from the left and Di Lorenzo is forced to intervene in turn with a header to push the ball back out of the net, deflecting the ball for a corner kick.
The second half presents itself with the same characteristics and neither team manages to prevail over the other.
The balance of the match was interrupted in the 22nd minute when Vecino picked up a non-perfect clearance from Kvaratskhelia and sent a low shot from long range that sent the ball into the net.
Napoli reacts with enthusiasm but with little clarity.
The offensive actions of the Neapolitans produce a header from Osimhen which hits the crossbar and a tight scrum in front of Provedel which has no effect because the Biancoceleste defense rejects all the Neapolitans' attempts to conclude.
A crossbar is also hit, on a free kick, by Milinkovic-Savic, one of the protagonists of the Biancoceleste feat.
Thus ends with the leaders who are forced to see the 'Maradona' ground violated for the first time in the championship and with Lazio celebrating and bringing home three golden points for the Champions League race.
However, the Napoli fans cheered Spalletti's players all the same and awaited the match against Atalanta next Saturday to resume the interrupted journey.