Inter Milan stumbled in their bid to retain the Serie A title after throwing away a two-goal lead to draw 2-2 at Parma on Saturday, giving Napoli a chance to cut the champions' league lead to a single point.
Goals in the first half from Matteo Darmian and Marcus Thuram appeared to have sent Inter on their way to moving six points clear at the top of the division ahead of their Champions League quarterfinal with Bayern Munich.
But Adrian Bernabe halved the deficit for Parma on the hour mark with a daisy cutter from distance, and the hosts were level nine minutes later when Jacob Ondrejka's strike was deflected past Inter goalkeeper Yann Sommer.
Inter have a packed April and came into Saturday's match in the wake of Wednesday's 1-1 derby draw with AC Milan in the first leg of their Italian Cup semifinal.
"We've had a lot of commitments, we'd just played a derby, and you can't always find the right spirit to get the three points," said Inter's assistant coach Massimiliano Farris to DAZN.
"The team couldn't find the mental or physical energy to contain Parma. We shouldn't have been in the position to concede those goals."
Moments before Ondrejka's leveller, Farris, in charge of Inter in place of suspended coach Simone Inzaghi, had substituted key players Lautaro Martinez and Hakan Calhanoglu.
Those substitutions, as well as the taking off star wing-back Federico Dimarco seconds before Bernabe's first-ever Serie A goal, left Inter toothless as they tried to regain the lead.
Inter now need in-form Bologna, who are fourth and chasing Champions League qualification, to stop Napoli on Monday night after an awful second half performance at the Stadio Ennio Tardini.
Saturday's draw ruined a special day for Thuram, whose 17th goal of the season came in his first match at Parma, where his father Lilian Thuram played in an all-star team which won the Uefa Cup, the Italian Cup and the Italian Super Cup in 1999.
Thuram junior was born in Parma two years before those triumphs and was playing in front of his dad, who watched his son's wild mishit somehow double Inter's lead on the stroke of halftime.
BAYERN BATTLE
Inter take on injury-ravaged Bayern in Germany on Tuesday with Inzaghi's side bidding to repeat the Serie A, Champions League and Italian Cup treble achieved 15 years ago under Jose Mourinho.
Italy defender Alessandro Bastoni was forced off at halftime and then seen with a large ice pack on his left knee, with Inter's defensive fragility also a worry for Inzaghi after his team again let the opposition back into the game instead of pressing home the advantage.
"With the number of games we're playing, an ice pack is the minimum you'd expect. It doesn't appear to be anything worrying," said Farris.
Parma are battling relegation and a fourth straight draw moved Cristian Chivu's side four points above Empoli, who sit just inside the relegation zone and host Cagliari on Sunday.
Milan came back from two goals down to draw 2-2 an entertaining match with Fiorentina but a point was not enough to boost their hopes of European football next season.
Tammy Abraham and Luka Jovic pulled Milan level after Sergio Conceicao's team conceded twice in the opening 10 minutes in front of angry supporters at the San Siro.
Fiorentina goalkeeper David De Gea kept Milan at bay with a series of stunning saves in the second half, and Dodo thought he had handed the away side the three points in the final minute only for his brilliant volley to be ruled out for offside.
Milan, in ninth, are eight points away from the Champions League spots and four behind Fiorentina, Lazio and Roma, the latter of whom sit sixth and in the Conference League spot.
Earlier, Como took a big step towards Serie A safety by winning 3-1 at regional rivals Monza and pulling 10 points clear of the bottom three.