In addition, Captain Paolo Cannavaro and fellow defender Gianluca Grava were cleared of all charges and are eligible to return to the club immediately.
Cannavaro was overjoyed after the ruling.
“I feel immense joy and am still crying, as I am so moved,” Cannavaro told Napoli's official website:
It has been a terrible time, a month in Hell. Now I feel liberated. I felt so bad during this time and can never forget when I went through in this month. I thank everyone who stayed close to me, from the club for all they did to the Coach and my teammates who comforted me every day.
Ex-keeper Matteo Gianello was banned for three years and three months for his involvement in the scandal. He claimed that he offered a potential fix to Cannavaro and Grava for the Sampdoria-Napoli match in May 2010, but that the pair turned him down.
Cannavaro and Grava were originally banned for six months for failing to report the attempted fix to authorities, but insisted they had never even been approached by Gianello.
The original fine was for €70,000, but following the appeal it was reduced to €50,000.
Club President Aurelio De Laurentiis was also full of excitement following the ruling.
“I am undoubtedly very happy. This is not just a victory for Napoli, but for all of Italian football and for justice,” he told Sky Sport Italia.
“I believed and continue to believe in justice. I thank the judges who listened to us and debated for many hours. At the end of the day, innocence makes justice great. It was a right and equal sentence.”
The return of Grava and Cannavaro adds some much-needed depth on their back line as they find themselves very much at the forefront of this season's Scudetto race.