Juventus' start to the season went from bad to worse on Wednesday, with the defending Serie A champions slipping to a 1-0 defeat at the hands of Sassuolo.
The loss is Juve's fourth in their opening 10 league games, and their first ever defeat to Sassuolo. It's a result that leaves them languishing in 12th spot on the Serie A standings, 11 points off the pace set by Roma.
After a tight opening to the match, striker Nicola Sansone gave Sassuolo an unexpected lead when he blasted a free kick into the top corner after 20 minutes.
Things went from bad to worse for Juventus when defender Giorgio Chiellini was sent off in the 39th minute after receiving a second yellow card.
Paul Pogba, Juan Cuadrado and Hernanes all came close to scoring an equaliser, but Sassuolo managed to hang on and claim a historic win.
Roma moved to top of the points table after beating Udinese 3-1 in the Italian capital.
Roma needed just five minutes to take the lead when midfielder Miralem Pjanic slotted the ball in from 10 yards out after some silky interplay with Maicon.
The hosts doubled their lead just five minutes later when Maicon scored after latching on to a pass from Edin Dzeko.
Gervinho made it 3-0 to Roma in the 64th minute before Udinese striker Cyril Thereau scored a consolation goal in the 77th minute.
Gonzalo Higuain and Dries Mertens scored to help Napoli to a comfortable 2-0 win over Palermo at Stadio San Paolo.
Napoli, who have now won seven consecutive matches in all competitions, took the lead in the 39th minute when Higuain received the ball at the edge of the penalty area and fired a low shot past Stefano Sorrentino to score in his fourth successive match.
Palermo had a number of opportunities to bring themselves level, but were wasteful. This came back to haunt them when Mertens sealed Napoli's victory in the 80th minute.
AC Milan rose from 10th to eighth on the standings after securing a 1-0 win over Chievo.
Both teams had their chances in the first half, but neither outfit could convert. It wasn't until the 53rd minute that Milan edged ahead through defender Luca Antonelli, whose curled shot went in after deflecting off the post.
Chievo continued to look to for an equaliser, but were unable to find one.
Atalanta pulled off a brilliant heist in their match against Lazio as they came back from a goal down to register a 2-1 win.
Lazio took the lead in the 19th minute through midfielder Lucas Biglia's magnificent free kick from 25 yards.
It wasn't until the 69th minute that Atalanta were level, with defender Dusan Basta scoring an own goal. Atalanta forward Alejandro Daro Gomez then scored with just four minutes remaining to lead his side to victory.
Goals either side of the half were enough to see Fiorentina record a 2-0 win at Hellas Verona.
Fiorentina kept Verona under pressure early on and were rewarded when defender Rafael Marquez committed an embarrassing mistake when he slotted the ball past his own goalkeeper.
Striker Nikola Kalinic doubled his side's lead in the 57th minute when he latched on to Giuseppe Rossi's cross and placed the ball into the back of the net.
Genoa midfielder Diego Laxalt's header in the last attack of the game ensured that his side did not walk away empty-handed as they drew 3-3 with Torino.
Laxalt gave his side a 1-0 lead in the 26th minute when he latched on to Leonardo Pavoletti's nod-on and headed the ball into the goal.
However, Torino brought themselves level just two minutes later when Maxi Lopez fired a shot past Genoa goalkeeper Mattia Perin.
Torino edged ahead in the 34th minute when Davide Zappacosta controlled Cristian Molinaro's cross and beat Perin with a low strike.
Genoa had to wait until the 67th minute to score an equaliser, which occurred when Pavoletti converted Serge Gakpe's through ball.
Genoa midfielder Panagiotis Tachtsidis then scored an own goal with one minute left. But, Laxalt came to the rescue with his header in the dying seconds to make it 3-3.
Frosinone midfielder Paolo Sammarco scored in stoppage time to lead his side to a 2-1 win over Carpi.
With both sides failing to make the most of their opportunities in the first half, it took 51 minutes for the deadlock to be broken, and Daniel Ciofani was the man to do so as he gave Frosinone the lead when he controlled Federico Dionisi's pass and slotted the ball into the back of the net.
Carpi midfielder Luca Marrone scored the equaliser in the 67th minute before both sides were reduced to 10 men five minutes later. Carpi striker Marco Borriello was shown a red card for his challenge on Frosinone midfielder Danilo Soddimo, who also sent off for his reaction to the challenge.
In the end, it was Frosinone that emerged victorious as Sammarco blasted the ball high into the net in stoppage time after being played through by Dionisi.
Sassuolo 1-0 Juventus
Roma 3-1 Udinese
Atalanta 2-1 Lazio
Frosinone 2-1 Carpi
Hellas Verona 0-2 Fiorentina
Milan 1-0 Chievo
Napoli 2-0 Palermo
Roma 3-1 Udinese
Sassuolo 1-0 Juventus
Torino 3-3 Genoa