The victory, which arrived courtesy of a winning goal from Alvaro Morata, means that the Old Lady will be crowned champions with three games remaining if second-placed Napoli fail to beat Roma on Monday afternoon.
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Juventus, who have now won 24 of their last 25 league matches, had the ball in the back of the net in the 17th minute when Sami Khedira turned home from close range, but the offside flag was raised following an acrobatic pass from Mario Mandzukic.
It appeared that the attacker was offside when he collected a fine through-pass from Nikola Kalinic, but the 22-year-old had timed his run perfectly and should have sent his side into a first-half lead against the champions.
Fiorentina were looking the most likely to make the breakthrough as the first period approached its latter stages and Milan Badelj and Cristian Tello both came close for the home side with long-range attempts.
It was Juventus that opened the scoring six minutes before the end of the first period, however, as Paul Pogba headed a Khedira cross into the path of Mandzukic, who smashed home from close range.
Fiorentina had a golden chance to level in the final moments of the half when Marcos Alonso met a corner from the right, but the defender somehow headed wide of the post under pressure from Daniele Rugani.
Tello found Josip Ilicic in a dangerous position as Fiorentina created the first chance of the second period in the 52nd minute, but the attacker sliced his effort over the crossbar as it remained 1-0 to the Old Lady.
Fiorentina continued to search for a leveller as the hour mark approached and indeed passed, with Mauro Zarate and Kalinic both testing Buffon between the Juventus sticks.
The home side finally had a deserved equaliser in the 81st minute when Kalinic lashed a 20-yard strike past Buffon, but their lead lasted less than two minutes as Morata turned home from close range after a weak strike from Patrice Evra to send Juventus back ahead.
Fiorentina had a golden chance to level the scores once again when Juan Cuadrado conceded a penalty in the 90th minute for a late challenge on Kalinic, but Buffon kept out Kalinic's resulting spot kick.
Incredibly, Kalinic was to have another wonderful chance to prevent Juventus from securing all the points, but the 28-year-old crashed a header off the crossbar in the third minute of additional time as the visitors moved to within touching distance of the title.