Napoli had seen previous appeals rejected and took the matter to the Italian Olympic Committee, which decided in favour of the club on Tuesday.
The ruling meant Napoli moved from fifth place to fourth, above Roma on goal difference.
Juventus lost the three points it was awarded but remained third, level on points with Napoli and Roma.
Also, Juventus and Napoli have played a match less than the rest of Serie A.
Napoli was issued a 3-0 loss and the one-point penalty for not showing up at Juventus on Oct. 4 because of coronavirus cases.
Last month, the FIGC court of appeal upheld the leagues ruling that Napoli did not have a valid reason for missing the fixture and should have followed the existing COVID-19 protocol, which was accepted by all clubs before the season.
The Italian league's protocol for coronavirus cases is the same as for UEFA rules. If a team has 13 available players, including at least one goalkeeper, the game can go ahead.
Napoli at the time had just two players who were positive for COVID-19 but argued it had been ordered not to travel by the local health authority.