MILAN (AP) " Inter Milan lost at Fiorentina 5-4 in one of the most incredible Serie A matches of the season on Saturday and left its European hopes hanging by a thread.
Inter led 2-1 at halftime, Fiorentina led 5-2 after 79 minutes, Inter scored its fourth in stoppage time and watched its equalizer attempt cleared off the goal-line.
Just over a month ago, Inter was hoping to sneak into the Champions League after a 7-1 victory over Atalanta but two points from five matches has seen it slip to seventh, two points behind AC Milan, which occupies the last qualifying position for the Europa League.
Milan hosts Empoli on Sunday.
"We have to understand why what happened happened," Inter coach Stefano Pioli said. "What we saw in the second half can't be my team ... we played for only 45 minutes. Then there was an inexplicable blackout.
"Since the Atalanta match we haven't had the right mental attitude. We are Inter and we can't play like this. We've reached the bottom. ... We can't throw away matches like we did in the second half today. Unfortunately this month we've thrown away everything we built."
Fiorentina, which also missed a penalty, moved to within one point of Inter, which hosts third-placed Napoli next weekend.
Matias Vecino broke the deadlock for Fiorentina early but Inter appeared to swiftly turn the match around with two goals in five minutes.
First, Ivan Perisic slotted home Antonio Candreva's low cross, then Mauro Icardi fired Joao Mario's through ball across into the bottom left corner.
Fiorentina should have equalized after halftime when it was awarded a soft penalty after Danilo D'Ambrosio was adjudged to have pulled back Khouma Babacar, but Federico Bernardeschi's weak spot kick saved by Samir Handanovic.
Davide Astori headed in the equalizer shortly after the hour mark, and Vecino again gave Fiorentina the lead two minutes later with his second of the match.
Babacar appeared to seal matters for Fiorentina with two strikes into the bottom right corner in the 70th and 79th minutes to make it 5-2.
But Inter wasn't finished.
Icardi controlled Perisic's pass in the area and fired in off the post two minutes from time, and headed in a corner in stoppage time to complete a hat trick.
Inter threw everyone forward and almost leveled from another corner which came out to Marcelo Brozovic, whose effort was cleared off the line by Astori.
ATALANTA 3, BOLOGNA 2
Atalanta let slip a two-goal lead before defender Mattia Caldara again came to its rescue to keep his side's European hopes alive.
Atalanta moved to fourth on the table, seven points ahead of Inter, and two above Lazio, which hosts Palermo on Sunday.
Atalanta took the lead less than three minutes in as Andrea Conti raced onto Alejandro Gomez's delightful through ball and fired through the legs of Bologna goalkeeper Angelo Da Costa.
Video replays showed Conti was offside.
Gomez had a hand in the second as well, in the 14th, with a ball which Andrea Petagna crossed in for Remo Freuler to turn in.
Bologna got back into the match two minutes later as Mattia Destro lunged in to direct Federico Di Francesco's pass into the roof of the net.
Di Francesco got on the scoresheet shortly after the hour as Atalanta failed to clear and he curled the equalizer into the bottom left corner.
However, Atalanta took all three points when substitute Bryan Cristante nodded on a corner and Caldara scored with 14 minutes remaining.
Bologna almost leveled but Atalanta midfielder Leonardo Spinazzola denied Destro with a goal-line clearance.