A hostile predawn confrontation involving three men in Serra Mesa led to a shooting that left one of them wounded Thursday.

Two of the men were arguing in the 3500 block of Afton Road at about 3 a.m. Thursday when the third armed himself with a shotgun, opened fire and then fled, according to the San Diego Police Department.

Paramedics took the victim to a hospital for treatment of gunshot injuries to his left shin, including a fractured tibia and fibula, Officer David O’Brien said.

The shooter, described as a heavyset, roughly 5-foot-6-inch man in his 30s with long black hair and wearing a black trench coat, remained at large at midday, according to police.

(File photo courtesy of the San Diego Police Department)