Bologna striker Adailton scored three minutes into injury time as they drew 1-1 with Juventus to prevent their hosts going top of Serie A.
With Sampdoria having beaten previous leaders Inter Milan, Juve could have replaced the Blucerchiati atop the standings with a win and seemed well placed when David Trezeguet put them ahead after 24 minutes.
But Bologna never gave up and salvaged a deserved point when Adailton converted Pablo Osvaldo's late cross.
Daniele De Rossi's last-gasp equaliser handed Roma a share of the spoils from a 1-1 draw in their clash with Catania.
The Sicilian outfit thought they had claimed their first triumph of the campaign courtesy of Takayuki Morimoto's first-half goal, only for De Rossi to ruin the party deep in stoppage time.
Catania finished the game a man light after substitute Gennaro Delvecchio was handed his marching orders for dissent soon after Roma restored parity.
Goalkeeper Marco Storari saved AC Milan from another embarrassing defeat as they only just managed to hold a lively Bari to a goalless draw at the San Siro.
The Apulian side attacked from start to finish and will wonder how they did not manage to come away from Milan with all three points as the Rossoneri once again disappointed in front of their own fans, who let their feelings known at the final whistle.
A late goal from Mauro Zarate spared Lazio's blushes at the Stadio Olimpico as the Romans salvaged a point from a 1-1 draw against Palermo.
The hosts looked to be heading for their third consecutive home defeat of the season following substitute Edison Cavani's 75th-minute opener for Palermo.
But Zarate popped up in the final five minutes to snatch a share of the spoils for Lazio.
Marek Hamsik struck twice in the second half at San Paolo to hand Napoli a second win of the season, 2-1 at the expense of struggling Siena, and ease the pressure on Roberto Donadoni.
Massimo Maccarone brought Siena level after 55 minutes after Hamsik's opener but the Slovakian's second sealed the win that leaves the visitors just above the relegation zone with four points from six Serie A outings.
Donadoni's position had come under scrutiny following three defeats in five matches but, having received the unequivocal support of president Aurelio De Laurentiis, the former Italy boss saw his side pick up a much-needed win.
Cagliari made it two wins from two with a solid 2-0 victory over Parma to underline the belief they have finally kick-started their season.
Jeda got them off to the perfect start with his seventh-minute goal and Daniele Dessena doubled his side's advantage shortly before the hour mark.
It brings to an end Parma's impressive record of not having tasted defeat at the Stadio Ennio Tardini since May 2008 and is a fantastic result for Cagliari, who before Wednesday's victory over Bari had lost all of their opening four fixtures.
Atalanta continue the search for their first win of the Serie A season after a 1-1 draw with Chievo at the Stadio Marc Antonio Bentegodi.
Simone Tiribocchi broke the deadlock for the visitors, but their lead lasted just five minutes with Sergio Pellissier hitting back for Chievo.
The draw was not enough to move Atalanta out of the bottom three, while Chievo sit eighth in the standings.
Two late goals gave Udinese all three points as they leapfrogged opponents Genoa thanks to a 2-0 victory.
Antonio Di Natale netted his eighth goal in six games in the 82nd minute to unlock a tight game, before Simone Pepe secured all three points one minute from the end.
The result takes the Bianconeri up to fifth while Genoa, who have now picked up just one point in their last three games, drop to sixth.
On Saturday, Sampdoria moved to the top of Serie A after shocking defending champions Inter Milan with their fifth win in six games, 1-0 at the Stadio Luigi Ferraris.
A goal from Giampaolo Pazzini in the 72nd minute was enough to decide a very tight, yet entertaining encounter, inflicting Inter's first defeat of the season.
Both sides had made a positive start to the season, with Inter dropping only two points so far and Samp seeing their four-game winning streak only ended by Fiorentina in midweek.
The Viola warmed up for the visit of Liverpool in the Champions League on Tuesday with a 1-0 victory over Livorno to move level on points with second-placed Inter.
Stevan Jovetic scored the only goal of the game from the penalty spot in the 76th minute as the Viola, who had Dario Dainelli sent off late on, made it two wins in four days to leapfrog Genoa into fourth place.
But the Viola had goalkeeper Sebastian Frey to thank for a string of marvellous saves to keep another crucial clean sheet.