Photo: Lauren Hernandez / The Chronicle Photo: Suzanne Espinosa Solis / San Francisco Chronicle

A pedestrian was taken to the hospital with lacerations to his head after a bicyclist plowed into him in San Francisco’s South of Market district on Friday evening, police and witnesses said.

A bicyclist riding a dark-colored 10-speed bike barreled down Fifth Street and crashed into an “elderly gentleman” who had just stepped off the curb to walk across Mission Street in the direction of the garage at Fifth and Mission, said witness Gary Morris, 67. One witness said the bicyclist was trying to beat the light.

“The elderly man went down and he just fell. There was no bracing himself. He was in total shock on his part,” Morris said. “We saw and heard his head hit the cement and bounce.”

The bloodied victim, who police did not identify, was immobile and silent for more than 40 seconds before he came to and started to talk to witnesses while still sprawled out on the street, Morris said.

San Francisco police officers and paramedics responded to scene, pulling the victim into an ambulance. He was taken to a local hospital for treatment, said SFPD Officer Frankey Nava.

Nava told The Chronicle that the victim had lacerations to his head but did not appear to sustain any major injuries.

The bicyclist’s condition was unknown, but he remained at the scene while police investigated.

“I couldn’t tell if the light was green when the bicyclist came through, but the man was no more than 18 or 24 inches off the curb when the bike hit him,” Morris said.

Morris and his partner, Ellen Whitney, 72, joined other witnesses at the corner to detail the incident to responding police officers.

Lauren Hernandez is a San Francisco Chronicle staff writer. Email: lauren.hernandez@sfchronicle.com Twitter: @LaurenPorFavor