In other results it was: Parma 4, Atalanta 3; Torino 2, Hellas Verona 2; and Livorno 1, Cagliari 1.
Napoli had won its opening four matches, while Sassuolo was the only team without a point in Serie A and was still reeling from a 7-0 defeat at home to Inter Milan on the weekend.
Napoli took the lead in the 15th minute when a cross was cleared straight at Blerim Dzemaili, who lashed it into the bottom left corner from 25 yards.
Sassuolo had scored just one goal in its opening four matches and Simone Zaza was again the scorer five minutes later, firing into the roof of the net from a tight angle following a Jasmin Kurtic through ball.
And Sassuolo held on for its first ever Serie A point.
The result means that Roma is the only team still with a perfect record following its victory against Sampdoria.
Roma was struggling to break down a resilient Sampdoria defense and Garcia's frustration got the better of him as he was sent to the stands 10 minutes into the second half for his protests.
Benatia broke the deadlock 10 minutes later with a wonderful solo effort. The Morocco striker wove his way through the Sampdoria defense, beating four players on his way into the penalty area. He then tripped but fired home as he fell.
Gervinho also scored his first Serie A goal after he was sent clear by Francesco Totti, two minutes from time.
Sampdoria winger Antonino Barilla was sent off for a second booking in stoppages
Milan was unbeaten at Bologna since 2002 but had endured a miserable start to the season with just four points from as many games and was missing the suspended Mario Balotelli as well as a number of injured players.
It took the lead in the 12th minute when Andrea Poli fired Robinho's smart pass across goal into the bottom left corner but Diego Laxalt leveled for Bologna in the 33rd following a swift counter.
Milan missed a series of incredible chances and Laxalt who is on loan from the Rossoneri's bitter rival Inter Milan headed in Lazaros Christodolopoulos cross seven minutes into the second half to put Bologna in front.
Cristaldo also celebrated his first Serie A start with a goal, extending Bologna's lead shortly after the hour with a diving header into the bottom right corner following Alessandro Diamanti's cross.
Phillipe Mexes had a shot crash off the crossbar and it seemed as if Milan was heading for a third defeat of the season.
However, Milan had recently come back with two late goals at Torino to secure a draw and it did so again. Robinho pulled one back in the 89th and played a part in the equalizer two minutes later. The Brazilian's header was saved but the rebound ricocheted to Ignazio Abate to snatch a share of the points.
"I believe that before Christmas we will be in another position," Milan coach Massimiliano Allegri said. "The other teams have started well and we have dropped points, but the team is growing and I have faith in my lads. I know that it won't be easy to finish in the top three but we have everything to go for it.
"I'm not disappointed with how we played. But I am angry because after the 3-3 we gave away the ball and risked conceding a fourth. They are things that should not happen. I am satisfied, but we aren't converting even 30 per cent of our chances and that can't happen either."
Juventus struggled to carve out opportunities in Verona and Chievo took a shock lead in the 27th minute.
Italy goalkeeper Gianluigi Buffon made a rare mistake, clearing a ball straight to Gennaro Sardo, who crossed in for Cyril Thereau to fire into the bottom left corner with a side-footed volley.
Juve leveled less than two minutes after halftime. Chievo goalkeeper pulled off a fantastic save to parry Fabio Quagliarella's header from Paul Pogba's cross. Quagliarella then drove the follow up onto the crossbar but eventually managed to scramble it into the back of the net.
There was controversy three minutes later. Another mistake by Buffon saw him only parry Simone Bentivoglio's shot. Alberto Paloschi fired in the rebound but was harshly ruled out for offside, sparking furious protests. The assistant referee had appeared to mistake Paloschi for Thereau who had been in an offside position.
Juventus took the lead in the 65th when Alessandro Bernardini dived onto Pogba's cross and turned it into his own goal.
