Lazio squandered a two-goal lead against Inter Milan as they drew 2-2 at the San Siro on Sunday and wasted a golden chance to take sole possession of third spot in Serie A.
Felipe Anderson's first-half double put Lazio in control but goals from Mateo Kovacic and Rodrigo Palacio late in the game salvaged a point for Roberto Mancini's 11th-placed Inter.
Sampdoria's Manolo Gabbiadini grabbed the equaliser in a 2-2 home draw with Udinese, while Genoa lost 2-1 at Torino.
Lazio are level with Napoli and Sampdoria on 27 points, 12 adrift of leaders Juventus, who meet the Naples club in the Italian Super Cup in Qatar on Monday.
AS Roma are in second place three points off the pace after being hled to a 0-0 draw at home by AC Milan on Saturday.
Lazio's Brazilian midfielder Anderson scored his first goal after less than two minutes, controlling a Stefan Radu cross and striking a clinical low shot past goalkeeper Samir Handanovic.
He grabbed his second in the 37th after moving in from the left wing with Handanovic stranded by another low strike.
"Unfortunately we made mistakes," Inter manager Mancini said.
"We seem to take two steps forward and one step back."
The second half belonged to Inter but they had to wait until the 66th minute when Croatia international Kovacic scored with a thunderous volley from just outside the area that Federico Marchetti got his fingers to but could not keep out.
"I haven't scored many goals in my career," 20-year-old Kovacic said. "But this is for sure the most beautiful."
Kovacic's strike woke up the crowd and inspired his team who 14 minutes later equalised when Danilo D'Ambrosio nodded on a free kick for Palacio to score his first of the season.
"Inter pushed with great force in the second half," Lazio manager Stefano Pioli told Sky Sport Italia.
"Unfortunately, we weren't able to maintain possession of the ball in the second half and they (Inter) were able to take advantage of two set plays."
In Genoa, Sampdoria's Pedro Obiang put the hosts in front after 15 minutes but Udinese turned the match around with goals from Alex Geijo and Danilo before the break.
Sampdoria substitute Gabbiadini, who is set to join Napoli in the January transfer window according to local media reports, headed them level on the hour before ninth-placed Udinese lost Thomas Heurtaux to a red card with two minutes to go.
"At times he (Gabbiadini) has lacked determination," Samp coach Sinisa Mihajlovic told Sky Sports. "Having him sit on the bench seems to have given him extra motivation."
Two goals from Polish international Kamil Glik gave lowly Torino a 2-1 home win over sixth-placed Genoa, who stay on 26 points, while mid-table Palermo chalked up a club record eighth straight unbeaten top-flight result by drawing 3-3 at Atalanta.
Alberto Paloschi's late header handed Chievo a 1-0 victory in their derby clash with fellow strugglers Verona.