A man was robbed of his cellphone on Mission Street near 23rd at around 2:30 a.m. on Thursday, according to police.
It was the fifth cellphone taken so far this month.
The 39-year-old victim was approached by a suspect who began punching and kicking him. The victim fell to the ground, and the suspect reached into his pocket and took his phone.
The suspect, described as a man in his 30s, then fled the scene on a bicycle.
The victim suffered a laceration to his head and was transported to San Francisco General Hospital for treatment.