A Queens man who sucker-punched a 64-year-old pedestrian for allegedly bumping into his girlfriend nearly five months ago surrendered to police on Monday to face a homicide charge.

Mathew Smith, 42, is accused of striking Patrick Gorman in head and knocking him to the sidewalk just after midnight on June 26 at the intersection of Queens Boulevard and Main Street in the Briarwood neighborhood.

A surveillance video released by police shows Gorman struggling to get to his feet after the punch. Gorman was taken to Good Samaritan Hospital, then transferred to Jamaica Hospital where he died later that day.

Investigators suspect that Gorman bumped into Smith’s wife, Elena Makarova, 39, and excused himself before being punched, the  Daily News reported.

Hours after the incident, Smith allegedly wrote on Facebook, “I had to put my hands on somebody last night,” as a status update.

Smith was charged with criminally negligent homicide and assault after surrendering at an East New York police station, investigators said.

The city’s Medical Examiner’s office determined last week that Gorman died from a combination of the punch and a stroke.

There was no information available as to whether Smith had obtained a lawyer who could comment on the charges on his behalf.