Thomas Sharkey, 21, died along with his father Thomas, 55, and Mr Sharkey senior's daughter Bridget, 8, after Scott Snowden and Robert Jennings set fire to the family home in Helensburgh, Argyll and Bute, in July 2011. The two men are serving life sentences for the killings.
Thomas's team-mates at Georgia Southern University won the Schenkel Invitational in Statesboro, Georgia, on Sunday, a tournament Mr Sharkey junior would probably have played in.
They plan to give their trophy to the victim's mother Angela Sharkey. Coach Larry Mays whose team had two holes in one, said: "Thomas Sharkey was there, in spirit, the whole time and we had the perfect Scottish [weather] for the last nine holes."