The Argentinian netted a brace and Patrice Evra, Giorgio Chiellini and Leonardo Bonucci scored as Max Allegri's outfit ended another successful season on a high.
Paulo Dybala scored twice as champions Juventus thrashed 10-man Sampdoria 5-0 to end the Serie A season on a high.
Massimiliano Allegri's men warmed up for next week's Coppa Italia final against AC Milan by bouncing straight back from their shock 2-1 defeat by Verona to canter to victory in front of a rapturous home crowd.
Five first-team regulars were restored to the Juve starting XI after Verona ended their 26-game unbeaten run last weekend and the hosts needed just five minutes to open the scoring through a Patrice Evra header, before Sampdoria defender Milan Skriniar was dismissed following a clumsy challenge on Mario Mandzukic.
Dybala's subsequent penalty was his 18th league goal of the season, with the Argentina international's 19th coming in style as he swept home from the edge of the area.
Giorgio Chiellini marked his 400th appearance for the club with a rare goal before a Leonardo Bonucci tap-in concluded the rout five minutes from time.
While Juventus were officially presented with the league title for a fifth consecutive season, defeat meant Samp ended the season having won just two of their last 10 games, piling the pressure on coach Vincenzo Montella, who was already subject to fan protests during the loss to rivals Genoa last time out.
The home supporters were already in a celebratory mood ahead of kick-off and an unlikely source gave them further reason to cheer inside five minutes as Evra peeled off his marker and leapt to convert Dybala's curling free-kick at the far post.
Juve doubled their lead ten minutes later from the spot, with referee Claudio Gavillucci awarding a penalty and sending off Skriniar for hacking down Mario Mandzukic after the Croatia striker had sprung the offside trap.
Dybala promptly stepped up and made it 2-0 by slotting the penalty low to Alberto Brignoli's right in confident fashion.
From that point it was damage limitation for the away side as the champions peppered their goal, Brignoli on hand to twice save smartly from Dybala.
Mandzukic then struck the bar with a looping header from a lofted Dybala ball before firing narrowly wide shortly after.
Dybala marked an excellent first-half performance with his second after 36 minutes, collecting the ball in space over 20 yards from goal and curling an unstoppable effort inside the left-hand post.
Juve picked up from where they left off in the second period, Chiellini denied by Brignoli after latching onto a Paul Pogba throughball shortly after the break in his first start since early April.
But the Italy centre-back celebrated his landmark in spectacular fashion in the 77th minute, smashing a half-volley into the top corner from the edge of the box after a cross was weakly punched away by Brignoli.
Bonucci met a knock-down from a corner to tap home from close range and complete Samp's humiliation, applying a fitting final touch to a remarkable league campaign before attention to turns to next Saturday's cup final at the Stadio Olimpico.
