Napoli visited Pescara Saturday in the Serie A and won 3-0 to postpone Juventus' title celebrations for at least another week.
Second-half goals from Gokhan Inler, Goran Pandev and Blerim Dzemaili left Napoli provisionally eight points behind league leader Juventus, with four rounds remaining.
The result means Juventus cannot secure a 29th title against Torino on Sunday and the defending champion will have to wait until next week's game against Palermo at least.
Napoli is also 10 points ahead of AC Milan, which hosts Catania on Sunday, in the race for direct entry into the Champions League.
"We should have unlocked this game immediately, but (goalkeeper Ivan) Pelizzoli was really good," Napoli coach Walter Mazzarri said. "I'd highlighted the importance of this game, the lads were a bit nervous. But then everything relaxed after the first goal.
"We had a bit of a dip, now we're back to form again. We've done better than last year but Juve has, too. We'll see if we can reduce the gap with Juve. We have taken an important step towards the Champions League."
Pescara was bottom of the league, eight points off safety.
Earlier, Udinese kept its hopes alive of securing a Europa League berth with a 1-0 win against Cagliari, picking up its fourth consecutive victory.
Cagliari striker Mauricio Pinilla was sent off in stoppage time after flying into the back of Giampiero Pinzi.
Atalanta drew 1-1 with Bologna, moving 10 points clear of the relegation zone, with Bologna a point further ahead.
Napoli, out to spoil Juventus' hopes, thought it scored quickly but Lorenzo Insigne, who fired Pescara to promotion last season, had his goal against his old club ruled out for offside.
Napoli broke the deadlock 45 seconds after halftime when Inler's 25-meter shot took a decisive deflection off Pescara defender Marco Capuano and flew into the bottom left corner.
Napoli doubled its lead in the 58th as Pandev controlled Christian Maggio's cross, spun and fired into the bottom left corner.
Pescara's night worsened when goalie Pelizzoli limped off with a groin strain.
Dzemaili sealed the match with a thunderbolt of a strike into the right side of goal from 30 metres out.
Cagliari played Udinese at Stadio Nereo Rocco in Trieste, where the Sardinian side is playing after abandoning its troubled Is Arenas stadium.
Roberto Pereyra, who hit the crossbar in the first half, scored in the 56th, curling an effort into the bottom right corner from the edge of the penalty area to help Udinese move provisionally into fifth.