Prosecutors say Jorge Alcantar is a member of the Sureno gang. Its rival is Fresno's Bulldog gang, which takes its moniker from the university mascot.
Prosecutors say Alcantar killed Stephen Maciel because the victim was wearing a red Fresno State shirt with a Bulldog on it. Maciel was not a gang member.
Jurors deliberated for less than a day before finding the 32-year-old guilty Thursday.
It was Alcantar's second trial. The first ended with jurors deadlocked on a second-degree murder conviction.
Alcantar faces 40 years to life in prison when he's sentenced on Oct. 28.