Juventus' poor start to the season continued as promoted Frosinone scored a last-minute equaliser for a 1-1 draw and their first ever point in Serie A.
The four-time reigning champions, who have yet to win at home, looked to be heading for their second victory of their campaign in the 50th minute when Simone Zaza struck his first goal since joining the Turin giants from Sassuolo this summer.
However, Leonardo Blanchard silenced the crowd at the Juventus stadium when he rose highest to head Danilo Soddimo's corner into the back of the net with one minute remaining and snatch a draw.
Leaders Inter Milan edged Hellas Verona 1-0 for their fifth win in as many games.
Brazilian midfielder Felipe Melo scored the only goal of the contest at the Giuseppe Meazza stadium in the 56th minute, rising highest to meet Alex Telles' corner.
Inter held on for the victory and in the process kept a clean sheet for the third straight encounter.
Fiorentina moved up to second after goals from Jakub Blaszczykowski and substitute Nikola Kalinic steered them to a 2-0 win against Bologna.
Blaszczykowski, the Poland winger on loan from Borussia Dortmund, scored his first club goal since joining the Viola in August when he broke the deadlock in the 71st minute with a right-footed shot from Matias Vecino's tee-up.
Kalinic then wrapped things up with eight minutes of normal time remaining, meeting a Marcos Alonso cross to strike home.
Sassuolo lie third -- 10 places ahead of Juve - after a 1-0 win at Palermo.
Sergio Floccari scored the only goal in the 36th minute and Palermo's search for a late equaliser was hampered by the 86th-minute dismissal of Luca Rigoni.
Torino suffered a 1-0 defeat at Chievo as Lucas Castro's 76th-minute goal meant the Flying Donkeys overtook Torino in the table -- as did Sampdoria, who won 2-1 against Roma.
Citadin Eder opened the scoring in the 51st minute and though Mohamed Salah equalised, Kostas Manolas' late own goal handed Samp the points.
Roma lie ninth after their first defeat of the season, just below bitter rivals Lazio, who beat Genoa 2-0.
Filip Djordjevic scored in the first half and Felipe Anderson added the second in between two dismissals for Genoa, Issa Cissokho in the 57th minute and Goran Pandev in the 86th.
Napoli, who had looked to have got their season going after following up their 5-0 Europa League victory over Bruges by thrashing Lazio by the same score, were held to a goalless draw by winless Carpi despite dominating possession and having 22 attempts at goal.