ROME (AP) -- Napoli's title hopes were dealt a severe blow with a 3-0 loss at Fiorentina on Sunday that leaves Juventus with a clear path toward a record-extending seventh straight Serie A championship.
Napoli played most of the match with 10 men after Kalidou Koulibaly was sent off for a last-man foul on Giovanni Simeone, who went on to score a hat trick.
Napoli coach Maurizio Sarri called it his squad's "worst match of the season."
After Koulibaly's red card and Fiorentina's first goal "we were completely lost," Sarri said. "Over the course of the season we've done well to handle these types of problems but today we didn't."
Napoli was left four points behind Juventus with three matches to play -- the same gap which existed until the Partenopei beat Juventus a week ago.
Juventus produced two goals in the final four minutes of a 3-2 win at 10-man Inter Milan on Saturday.
However, Juventus will have to overcome an injury to striker Mario Mandzukic, who had 10 stitches applied to a deep cut in his left ankle after getting stepped on by Matias Vecino against Inter.
In Florence, Koulibaly was first shown a yellow and a penalty was awarded since the referee believed the foul had occurred inside the area. But after VAR help, the referee ruled that the foul had occurred outside the area and changed the card from yellow to red.
Simeone, the son of Atletico Madrid coach and former Argentina international Diego Simeone, finished off a counterattack later in the first half by shooting under the legs of goalkeeper Pepe Reina.
Then after the hour mark, Simeone was quickest to a rebound following a corner and scored from close range. He then added another from a counterattack in the 90th, running past a confused Mario Rui for his 13th of the season.
"Clearly, having an extra man after eight minutes was a huge advantage," Fiorentina coach Stefano Pioli said. "We had the right ideas even with 11 against 11, but we should have scored more goals earlier on.
"We knew Napoli could be dangerous, so we tried to pass the ball and never stopped pressing," Pioli added. "There's no such thing as a perfect performance, but I think we came pretty close."
Fiorentina is ninth, four points below the Europa League spots.
AC Milan ended a five-match winless streak with a 2-1 victory at Bologna to revive its pursuit of a Europa League spot.
Hakan Calhanoglu and Giacomo Bonaventura scored in the first half for the Rossoneri, which had lost two and drawn three since beating Chievo in mid-March.
Milan remained one point behind sixth-place Atalanta, which beat Genoa 3-1, in the fight for the last Europa League spot.
Milan coach Gennaro Gattuso didn't give his squad any days off this week following a 1-0 loss at home against Bologna last weekend, acknowledging that the club had "touched bottom."
Calhanoglu was set up by Patrick Cutrone to score from beyond the area in the 34th.
Bologna thought it had equalized four minutes later but what would have been Riccardo Orsolini's first Serie A goal was waved off by the VAR for a handball in the buildup by Rodrigo Palacio.
Bonaventura then took advantage of a defensive mistake and fooled his marker before firing in an angled shot.
Sebastian De Maio pulled one back for Bologna with a header after the break.
Musa Barrow, Bryan Cristante and Josip Ilicic scored for Atalanta.
LAZIO ON COURSE
Lazio won 1-0 at Torino to stay level on points with third-place Roma and on course for a Champions League berth.
Roma and Lazio are each four points ahead of Inter.
Sergej Milinkovic-Savic scored with a header early in the second half for Lazio after Torino goalkeeper Salvatore Sirigu saved an early penalty from Luis Alberto.
Lazio striker Ciro Immobile exited in the first half with an apparent muscular injury. Immobile tops the league scoring chart with 29 goals.
VERONA ON THE VERGE
Hellas Verona was left on the verge of relegation after a 3-1 home loss to Spal, which moved one spot above the drop zone.
With bottom Benevento already relegated, Verona is in penultimate position, six points behind Chievo Verona and seven behind Spal.
After Mattia Valoti's opener for Verona, Spal struck back with goals from Mohamed Fares, Felipe and Jasmin Kurtic.
Chievo fired its coach, Rolando Maran, a day after a 4-1 loss at 10-man Roma. Youth squad coach and former Chievo captain Lorenzo D'Anna will replace Maran for the final three matches of the season.
Cagliari was also in danger after a 4-1 loss at Sampdoria left the Sardinian club two points above the relegation zone, while 15th-place Crotone gained some breathing room with a 4-1 win over Sassuolo.
Meanwhile, former France fullback Bacary Sagna scored a 90th-minute equalizer -- his first goal in Serie A -- as Benevento drew 3-3 with Udinese, which ended an 11-match losing streak.