Police on Wednesday released disturbing surveillance video showing a vicious sucker-punch that led to the death of a 64-year-old man in Queens.

Patrick Gorman was walking near the corner of Queens Boulevard and Main Street in Briarwood when he bumped into the attacker’s girlfriend just after midnight on June 26, cop sources said.

“Excuse me,” Gorman said, before the man belted him in the face, sources said.

The video shows the male suspect punching Gorman, who is seen falling squarely on his back as the duo calmly ambles off.

The victim tries to get back on his feet and then collapses.

Gorman was taken to Jamaica Hospital, where he died the next day at about 9 a.m., police said.

The city medical examiner ruled Gorman’s death a homicide last week, said a spokeswoman for the agency.

Gorman died from blunt force trauma to the head with a concussion to the brain and a combination of a stroke and a contributing condition of hypertensive and atherosclerotic cardiovascular disease, according to the medical examiner.

Gorman’s neighbor John Rynkowski, 47, said that Gorman, a Mets fan, had just returned to his Queens home from Baltimore and Philadelphia for ball games the day of the attack.

“Whenever he had off he would go to baseball games in different cities,” said Rynkowski who works at Citi Field and would often see Gorman there. “He was really nice guy. He loved baseball.”

Rynkowski said that cops should have released the surveillance video of the attack sooner.

“The cops took forever [to release the footage]. They should have released it right away,” he said. “It’s usually a safe area. I was very upset when it happened. Everybody in the building is upset.”

Leon Leone, 67, a resident at Gorman’s Briarwood building also echoed concern about the timing of the release of the video.

“I still don’t understand why it took so long,” said Leone, a member of Briarwood Action Network — the community organization that petitioned cops two years ago to install the security camera that captured the assault.

Leone called Gorman, “a very low key, quiet person. He never bothered anybody, a great neighbor. It’s the good people that go.”

“I just hope that justice will be done,” he added.