Seattle police detective Mark Jamieson says the man was walking through the park near the basketball courts around 8:30 p.m. when he was approached by another man who asked him for the time.
When the victim pulled out his cell phone to read the time, the suspect grabbed the phone and began to walk away, Jamieson said.
The victim tried to physically take the phone back, but the suspect brandished a silver-colored handgun and pointed it at the victim. The victim fled and called 911 from another location.
Officers responded and searched the area but did not locate the suspect.
He is described as a black male in his 20s, standing about 6 feet tall, with a thin build and wearing a black-and-grey hooded sweatshirt. The victim was not injured.