Juventus spurned the chance to move eight points clear of Napoli and Lazio after being held 1-1 by Genoa in what was Davide Ballardini's first game back in charge of the visitors.
Antonio Conte's side had relaunched their title defence with a resounding 4-0 win over Udinese last week when both Napoli and Lazio drew in their respective fixtures.
But despite dominating a pulsating encounter in Turin, Juventus grudglingly settled for a share of the spoils after second-half substitute Marco Borriello levelled Fabio Quagliarella's opener for the hosts.
Juventus created several chances in the final 20 minutes but came up short, and were left furious after being denied a solid penalty claim after the ball came off the arm of Swedish defender Andreas Granqvist.
Conte was still livid when he spoke to Sky Italia after the match: "Even a blind man would have seen it was a penalty!
"I'll accept it if they admit their error, but hearing a referee say 'I didn't feel ready' to give the penalty is not normal. This is not football."
Earlier in the match the ball had also came off the arm of Mirko Vucinic without the referee reacting, prompting Ballardini to say: "If we're going to talk about individual incidents we should talk about Mirko Vucinic's handling offence in the first half, but then we'd never hear the end of it."
Juventus now have a six-point lead over Napoli, who travel to Parma on Sunday, with Lazio third, also on 43 points, after being stunned 1-0 at home by Chievo.
Juve started without injured midfielder Andrea Pirlo but with Claudio Marchisio dropping back to his usual midfield role having played as a second striker in the 1-1 Cup draw with Lazio in midweek.
It took Juve all of 22 minutes to create an opening. Marchisio latched on to Paul Pogba's lob from outside the area but failed to make great contact as his effot went wide.
Just before the half hour Chilean midfielder Arturo Vidal sent a curling free kick over the crossbar and then Leonardo Bonucci rose to meet Marchisio's freekick from the right only for his header to sail wide.
A Quagliarella toe poke from Stephan Lichsteiner's dipping cross slipped just wide of the post and Genoa breathed another sigh of relief when their 'keeper Sebastien Frey stopped Martin Caceres from close range after the Uruguayan connected with a head-on from a free-kick.
The opener appeared to be on its way, and duly arrived with Quagliarella sending the ball off a defender and into the net after latching on to Lichsteiner's cross after the Swiss midfielder's smart run down the right.
Minutes later Ballardini, appointed to replace sacked Gigi Del Neri in midweek, made a double substitution that was to bear fruit.
Andrea Bertolacci and Marco Borriello replaced Ruben Olivera and Ciro Immobile respectively and on 68 minutes Borriello got his head to Juraj Kucka's delivery at the far post after the Slovakian's incisive run.
Genoa, however, were forced to play the final 15 minutes with 10 men when Antonio Flores limped off after all the substitutions had been made.
It allowed Juventus - who in Italy have long held a reputation for being given the rub of the green -- laid siege to the Genoa goal but were thwarted by Frey, the post and an apparently stubborn referee.
On 79 minutes Vucinic got his foot to a cross but failed to connect and moments later a superb free kick from strike partner Sebastian Giovinco hit the left upright.
Substitute Stefano Beltrame then tested Frey with a well struck shot after dispossessing a defender and showing good control on the edge of the area.
In the third minute of injury time Juve were denied what appeared to be a stonewall penalty after the ball clearly came off the arm of Granqvist.
Vucinic and Lichsteiner were cautioned for protesting and at the final whistle a livid Conte remonstrated with officials before leaving the pitch.
Earlier, an Alberto Paloschi strike in the 61st minute handed Chievo a shock 1-0 win which derailed Lazio's title hopes.