Usuthu have suffered the consequences of supporters misbehaving during their Absa Premiership fixture against Mamelodi Sundowns on March 2.
The incidents took place at King Zwelithini Stadium, where supporters hurled missiles onto the pitch after the referee's assistant allowed for Sundowns' third goal on the night despite appeals for off-side.
The PSL initially charged the club for "contravening the Safety and Security Manual (Compliance Manual)" as well as "failing to provide adequate security personnel".
They have since been acquitted of exceeding the stadium capacity, but will have to pay a substantial amount of money over their other charges.
A statement from the League reads as follows: 'The Premier Soccer League Disciplinary Committee has found AmaZulu FC guilty and fined the club R640 000.00 of which R320 000.00 was suspended for a period of 24 months provided they are not found guilty of similar offences.
'AmaZulu were charged for spectator misbehaviour and failure to provide adequate security during their Absa Premiership fixture against Mamelodi Sundowns on 02 March 2018 at King Zwelithini Stadium.
'The match was interrupted for a few minutes by spectators throwing missiles.
'AmaZulu were acquitted of charges of overselling tickets and exceeding the stadium safety capacity.'
Usuthu will host Downs at the same venue in Umlazi on Sunday.
The PSL yesterday announced Kaizer Chiefs will have to play three matches (one suspended) behind closed doors after their fans went on a rampage at Moses Mabhida Stadium in April following a 2-0 loss to Free State Stars in the Nedbank Cup semi-finals.