Peter Neville and son Daniel, 14, of Metford, say their trip to Gosford's Bluetongue Stadium was tarnished when some Central Coast Mariners fans harassed them.
Daniel caught one of Danny Vukovic's gloves, which the Central Coast goalkeeper had thrown into the crowd at the match's end.
Mariners supporters swamped Daniel in the excitement. He said some persisted, tugging at the glove and saying he did not deserve the memento because he was a Newcastle Jets fan.
Mr Neville said he was disgusted when several men yelled abuse at his son, but then feared for their safety when one of the men threatened them.
"We actually felt quite threatened, that we were going to be physically hurt."
A police officer intervened and security staff escorted them out of the stadium.
It was a poor end to what was a special match for the pair the first Daniel had been well enough to attend since completing chemotherapy for a brain tumour.
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