Inter Milan rescued a point with a late 1-1 draw at Torino Sunday but handed local rival AC Milan the advantage in the Serie A title race Sunday.
The other title hopeful Napoli, in the meanwhile, leapfrogged the reigning champion into second place with a 2-1 win at Verona.
Alexis Sanchez hit the leveler in the third minute of the stoppage time of an entertaining encounter in Turin which left Inter in third, four points behind Milan.
Simone Inzaghi's side has a game in hand, but it is now looking over its shoulders at Juventus, who is only three points behind its old rival in fourth after stringing together a 14-match unbeaten run.
That would have been unthinkable at the turn of the year when Inter was four points clear at the top and 12 ahead of Juve but Inter is ragged after looking imperious before Christmas.
"We know that we need to do more, have a different approach to these games, if we want to retain the title," Inzaghi admitted to DAZN.
Sanchez's equalizer was laid on by Edin Dzeko, who was Inter's worst culprit in front of goal after heading just wide on the hour and then nodding over from point-blank range moments before his Chilean teammate did the honors.
However, Inter could easily have lost in a deeply disappointing display.
After Brazilian defender Bremer gave the hosts the lead with 11 minutes gone, Samir Handanovic brilliantly tipped wide Armando Izzo's free header in the 64th minute.
Seconds before Robin Gosens had saved his goalkeeper with a desperate lunge to stop Josip Brekalo from scoring what would have been a superb individual goal after the Croatian international weaved his wave into the box.
They were also saved by the officials when Andrea Ranocchia was somehow ruled to have not fouled Andrea Belotti in the area nine minutes before the break, a decision that left Torino baffled.
"I went to (referee Marco) Guida and told him that it was a stonewall penalty, and he said to me 'VAR didn't call me, so I must have made the right decision,'" said Torino's sporting director, Davide Vagnati.
"You can talk about our brilliant performance and Inter's determination but if there's a penalty then they have to give it to us."
Victor Osimhen struck the first of his brace for Napoli, which kept his side three points behind Milan, in the 14th minute at the Stadio Bentegodi by thumping home a perfect header from Matteo Politano's cross.
In an eventful match for both Osimhen as the rest of his team, at one point it looked as though Napoli would have to do without its star forward for over half an hour when the 23-year-old was out of action for four minutes with a shoulder problem following a clash with Koray Gunter.
He carried on however and lashed in his crucial ninth league goal of the season in the 71st minute before snatching a camera and taking a snap of the Napoli fans.
"(Kalidou) Koulibaly gave me the camera to take a picture of the fans who have been amazing from the blast of the whistle to the very end. I think they deserved to get a shot," he told DAZN.
Verona, whose hardcore fans caused outrage in the run-up to the match with a banner that indicated the coordinates of Naples as a bombing target for Russia, had its hopes of continental football next season dented despite Davide Faraoni pulling a goal back shortly after Osimhen's second.
It is seven points behind both Roma and Atalanta who occupy sixth and fifth after their respective draws with Udinese and Genoa.
Atalanta looks to have forfeited its fight for the Champions League after a goalless stalemate with struggling Genoa, who has now drawn all seven matches under coach Alexander Blessin.
Gian Piero Gasperini's Atalanta is eight points behind fourth-placed Juventus, albeit with a game in hand.
Both Atalanta and Roma can be overtaken by Lazio, which is two points behind the pair before its match with Venezia in Rome on Monday night.
