Judge George Maluleke ruled in the High Court in Johannesburg that Maarohanye and Tshabalala were guilty of culpable homicide – and not murder – for killing four school children during a drag racing accident.
The pair was initially handed 20 years for murder.
On Wednesday, their sentences were reduced to 10 years, two of which were suspended.
The sentences would be backdated to October 2012 when the pair was first sentenced and jailed.
Maarohanye and Tshabalala were also initially sentenced to four years in jail for two attempted murder convictions and another year for driving under the influence of drugs and racing on a public road.
The attempted murder convictions were set aside.
The pair was found guilty of murder, attempted murder, driving under the influence of drugs, and racing on a public road by the Protea Magistrate’s Court, Soweto, on October 16, 2012.
They crashed their Mini Coopers into a group of schoolboys in Protea North, Soweto, on March 8, 2010. Four boys – Prince Mohube, Mlungisi Cwayi, Andile Mthombeni, and Phomello Masemola – were killed. Frank Mlambo and Fumani Mushwana were left permanently brain damaged.