AC Milan's title aspirations were dealt a severe blow after Fiorentina snatched a 2-1 win at San Siro on Saturday.
Amauri scored a dramatic late winnner to fire struggling Fiorentina to a 2-1 win at AC Milan on Saturday and boost his former club Juventus's title hopes.
Juve travel to Palermo later on Saturday and can leapfrog champions Milan if they win.
The Brazilian-born Italy international's goal ruined Antonio Cassano's return to first team action following heart surgery.
Cassano had not played since October after falling ill following a match at Roma.
He had suffered a minor stroke and needed an operation to fix a heart defect.
But his entry late on did little to inspire a reaction from an out-of-sorts Milan.
The hosts had been gifted the opener when Matija Nastasic was harshly adjudged to have fouled Maxi Lopez in the box.
Zlatan Ibrahimovic stroked home the spot-kick and Maxi Lopez later hit the post as Milan threatened to run away with the match.
But Fiorentina stuck doggedly to their task and equalised when Lorenzo Di Silvestri played Stevan Jovetic in behind the backline and the Montenegro playmaker beat goalkeeper Christian Abbiati.
And Amauri struck a minute from time following a Philippe Mexes mistake, playing a one-two with Jovetic before clipping the ball home.
Fiorentina boosted their own survival hopes, moving up two places to 15th and maintaining a five-point gap to the drop zone.
Udinese moved up into a Champions League qualifying position with a 3-1 win over Parma.
Ghana midfielder Kwadwo Asamoah opened the scoring on the stroke of half-time as he arrived late into the box to shoot home from the penalty spot.
Captain Antonio Di Natale added the second on 56 minutes as he controlled a cross at the back post before lashing home on the volley.
Alessandro Lucarelli pulled a goal back six minutes from time after Asamoah failed to clear a corner.
But the Ghanaian added his second in stoppage time in almost identical fashion to his first.
The northerners are now level on points with Lazio, who previously held third spot, ahead of the Romans' evening clash with Napoli.
Roma's Champions League qualification hopes hit a bump in Puglia as they were thrashed 4-2 by lowly Lecce.
Colombian Luis Muriel and former West Ham forward Daniel Di Michele both scored a brace as Lecce boosted their survival hopes.
Roma scored two consolation goals in the last two minutes through Bojan Krkic and Erik Lamela.
Roma remain four points behind third spot but could yet lose more ground in the evening.
Inter Milan played out an entertaining 2-2 draw away to Cagliari, in a match played in Trieste, 500 miles away from the hosts' Sardinian home, due to an unplayable pitch.
Cagliari opened the scoring after just five minutes as Daniele Astori acrobatically volleyed home from a corner with his back to goal despite being dragged down by Andrea Ranocchia.
But the lead lasted only a minute as Mauro Zarate twisted and turned on the edge of the box before crossing for Diego Milito, who found himself alone in front of goal as the Sardinians' defence pushed up.
The hosts went back in front just after the hour mark as Daniele Conti crossed for Mauricio Pinilla, who had snuck in behind Javier Zanetti, to plant a firm header beyond goalkeeper Luca Castellazzi.
But the Chilean goalscorer was then incredibly shown a second yellow card for merely lifting his shirt in celebration to show his tummy.
Again Inter hit straight back with Diego Forlan's cross luckily falling to Esteban Cambiasso as he tried to burst between two defenders, the Argentine reacting quickly to prod home after all three players had lost the flight of the ball.
Inter closed in on a Europa League spot as they now trail Roma by just two points.