The New Hampshire father of two who died after an incident at Gillette Stadium during the New England Patriots game Sunday had been punched in the face and knocked unconscious by a Miami Dolphins fan, according to a witness.

Dale Mooney, 53, was treated at the scene by EMTs and rushed to a hospital after what had been described as an “apparent medical event,” but was pronounced dead shortly before midnight.

A spectator has now claimed that he witnessed a physical altercation between Mooney and a Dolphins fan.

“The Dolphins fan walks over and clearly punches him in the face,” Joey Kilmartin, of Nashua, New Hampshire, told MassLive.

“(He) gets knocked out and you can tell right away he’s not OK.”

Kilmartin told the news outlet that Mooney also had gotten into a physical confrontation with other fans toward the end of the fourth quarter.

He said Mooney never regained consciousness after being punched and that the EMTs performed CPR on him before rushing him to Sturdy Memorial Hospital in Attleboro.

“It’s an unfortunate situation. I feel bad for the family,” said Kilmartin, who described the incident to Foxborough police.

He provided a video of the incident to WCVB, which published images from the clip showing Mooney getting his shirt pulled.

The footage shows Mooney approaching the other fans on the 300 level of the stadium.

“He basically grabbed another fan,” Kilmartin told WCVB.

“They started tussling around for a few minutes. At one point, another fan walked over. He punched him … and the man just went out. It was pretty hard to watch.”

Mooney’s wife, Lisa, said she feels “numb” and is seeking answers about the tragedy.

“I want to know what happened. What caused this?” she told WCVB.

“I just don’t understand why people have to go to that extreme. Why can’t it just be fun? That’s all it’s supposed to be — a fun family event.”

Lisa said her husband — a father of two and season ticket holder for 30 years — went to the game with three friends who told her they were taunted by other fans.

“It takes a lot to get him mad. He has the patience of a saint. I don’t know what happened,” Lisa told the outlet, adding that her husband had no medical condition that she knew of.

No charges have been filed, though Kilmartin told MassLive that he witnessed cops take one man into custody.

Massachusetts State Police assigned to the Norfolk DA’s Office have been assigned to the investigation.

Autopsy results are pending.