AC Milan missed the chance to go second in Serie A on Saturday after falling to a 2-1 defeat at Fiorentina, ending a recent upturn in form for the reigning champions.
Nicolas Gonzalez's penalty three minutes after the break and a late Luka Jovic header earned Fiorentina the three points and ended Milan's four-match winning streak ahead of their Champions League showdown at Tottenham on Wednesday.
Theo Hernandez netted in stoppage time for Milan who are fourth, level on 47 points with local rivals Inter ahead of their match with Lecce on Sunday.
Stefano Pioli's side, without suspended star attacker Rafael Leao, are one behind Lazio after their stunning win at runaway leaders Napoli on Friday moved the capital club second.
Roma will move above Milan on goal difference if they beat Juventus on Sunday night.
"Fiorentina were better than us today, but not because our minds were on Tottenham," said Pioli to Sky.
"That will be a different match, it's a knockout game and tonight's performance won't affect us, just as Tottenham won't be affected by their two consecutive defeats."
Fiorentina meanwhile stay 12th, level on 31 points with Torino, after a win which came on the fifth anniversary of former Viola captain Davide Astori's death.
Astori died in his sleep in a hotel room on this day in 2018, aged just 31, when Pioli was in charge at Fiorentina.
The former defender came through the youth ranks at Milan and was applauded by the more than 40 000 fans at the Stadio Artemio Franchi when play was stopped in the 13th minute in honour of his old shirt number.
"We had been lacking a win against one of the top teams but today the boys were superlative, they all played with great quality and determination," Fiorentina coach Vincenzo Italiano told DAZN.
"If we keep playing like this we'll have some joy between now and the end of the season."
DRAB DRAW FOR ATALANTA
The hosts would have been ahead midway through the first half had Fikayo Tomori not been on hand to clear Giacomo Bonaventura's scuffed close-range strike off the line.
But it was the England international who handed Fiorentina the chance to take the lead when he was spun by Jonathan Ikone and then clumsily brought down the French attacker in the penalty area.
Gonzalez coolly placed his spot-kick past Mike Maignan and from there Fiorentina, pushed by passionate support, rarely looked like being pegged back.
Pietro Terracciano kept out an Olivier Giroud header and then rushed out to deny Hernandez just before the hour mark but apart from the France full-back's consolation goal that was it from a poor Milan.
They were almost saved when referee Marco Di Bello inexplicably gave a penalty for handball when Artur Cabral headed a corner clear in the 78th minute, but the decision was quickly overturned by Di Bello after checking the pitch-side monitors.
And once Jovic dove to head in Dodo's pinpoint cross with three minutes remaining that was that.
Defeat for Milan will be a relief to Atalanta, whose bid for Champions League football took another hit after a drab goalless draw with Udinese.
Gian Piero Gasperini's side stay sixth and five points off Italy's top four following an uninspiring performance against their off-form opponents in Bergamo.
Rafael Toloi went closest for the hosts, his dipping strike in the final minute brilliantly tipped away by Marco Silvestri.
Udinese have won just once since early October and sit ninth, level on 32 points with Monza who beat Empoli 2-1 in Saturday's early match.