It was Gwynn's third ejection in 11 seasons as coach at his alma mater. The Aztecs lost 11-7 to New Mexico.
Plate umpire Dominic Giarratano called SDSU's John Spirk out and ejected him after he collided with New Mexico catcher Alex Real in the seventh inning, believing the SDSU player had thrown an elbow.
Gwynn came out to argue and was ejected by Giarratano. The three umpires held a long discussion and reversed the decision to eject Spirk. The umpires decided he put his arms up to protect himself during the collision.