A late Emanuele Calaio freekick earned battling Genoa a shock 1-1 draw away to Napoli on Monday, when Fiorentina also snatched a late share of the points in a 2-2 draw away to Parma.
Napoli looked to have done enough to claim all three points at the San Paolo after Gonzalo Higuain ran on to Marek Hamsik's through ball to beat Mattia Perin in the 18th minute.
But Rafael Benitez's men failed to build on their lead and paid the price less than 10 minutes from the end when Genoa won a freekick after a foul by Dries Mertens which earned the Belgian a yellow card.
Calaio was handed the honours and from nearly 30 metres out stepped up to curl the ball over the wall and in off Pepe Reina's post as the Spanish 'keeper looked on in shock.
Despite being mobbed by teammates, Calaio did his best not to celebrate -- the striker is effectively still a Napoli player having been loaned to Genoa last season.
"I've scored in the only stadium I didn't want to score in, but it was a beautiful goal," Calaio told Sky Sport Italia.
"I'm sorry to have scored at the San Paolo because I spent a long time here, but when the coach gave me the chance I had to step up and honour this shirt.
"It's the third freekick I've scored in my career, but this one was special."
Instead of reducing the gap to second-placed Roma to four points, Napoli are now six behind Rudi Garcia's men, who themselves are nine behind leaders Juventus albeit with a game in hand.
Napoli's setback comes only days after being held to a draw away to Europa League last 32 opponents Swansea, and four days ahead of the return leg in Italy.
Benitez suggested his side had underestimated the visitors: "We should have settled the game much earlier but we were just missing the final touch. We need to learn the importance of these kinds of games."
Defender Federico Fernandez believes Napoli can still reach their target of second spot, but said the focus is now on Swansea.
"It's still our objective," he said when asked about the growing gap to Garcia's title challengers.
"But we have to work on the little details that can help you win games. We can climb back up (the table)."
He added: "Swansea is a crucial game for us. We have to get focused on this straight away and start working in the coming days to do better than we did tonight."
Fiorentina remain fourth, six points behind Napoli, although La Viola had to thank Mati Fernandez for helping grab a share of the spoils five minutes from the final whistle.
The hosts broke the deadlock through striker Antonio Cassano six minutes from the interval although only two minutes later Juan Cuadrado got on the end of Alessandro Matri's delivery to beat goalkeeper Antonio Mirante to level.
Former Fiorentina flop Amauri restored Parma's lead, in the 51st minute, from the penalty spot after Nenad Tomovic fouled Jonathan Biabiany just as the Frenchman was getting his head to a cross.
The visitors suffered another blow two minutes later when Modibo Diakite, who had been booked just before the half hour for a foul from behind on Cassano, saw red after another foul on the former Inter and AC Milan striker.
Despite being a man down Fiorentina pressed forward looking for an equaliser and when the visitors won a late free kick Fernandez spoiled the Parma party with a superbly-struck curling effort which had Mirante scrambling back into his own net.
Parma brought Raffaele Palladino off the bench and he flashed a header wide of the goal within a minute of coming on.
The match finished level, but on a sour note after a scuffle between Borja Valero and Gianni Munari led to both players being sent off in the fourth minute of added-on time.