The Police Investigations and Review Commissioner (PIRC) concluded that the two British Transport Police (BTP) officers involved had handled the situation professionally and that the use of the spray by one of them was proportionate.
The incident happened in the Bridgeton area of Glasgow on October 22, the day of Celtic's Champions League clash with Ajax at Parkhead.
The BTP officers working at Bridgeton station heard people shouting and found a row involving a group of more than 15 rival supporters had broken out.
The men ignored repeated warnings from the BTP officers, including warnings that the spray, known as captor spray, would be used if they did not stop fighting.
One of the officers used the spray, after which point the men dispersed.
Publishing his findings, commissioner Professor John McNeill said the officers were outnumbered by the fighting fans.
He said: "I am satisfied that the officers managed the incident professionally. Had the officer not used the captor spray, there is a likelihood that the situation would have continued to escalate and place those involved, members of the public and police officers at risk."
The commissioner did, however, recommended that BTP update their procedures for using the spray in areas other than railway premises.