One of three Americans who helped thwart a terror attack on a Paris-bound train was stabbed in his home state of California — apparently after coming to a woman’s rescue, authorities said.

Airman Spencer Stone, 23, was stabbed in Sacramento after he got into a fight with a group of men as he was leaving a bar with friends, Ken Bernard, the city’s deputy chief of police, told reporters.

He said police received a call at 12:46 am from a passerby who witnessed the incident.

Bernard said officers who arrived at the scene found Stone with multiple stab wounds to his upper torso.

He was rushed to a nearby hospital where he was listed in serious condition after undergoing two hours of surgery.

“He is currently being treated for what appears to be non-life threatening but very significant injuries,” Bernard said, adding that two male Asian suspects were being sought in connection with the attack.

A source close to the investigation told AFP that Stone was apparently trying to defend a woman being harassed by a group of men outside the bar when an argument escalated and he got stabbed.

It was unclear if the woman was with Stone.

“A woman was being harassed and he got involved,” said the source, who spoke on condition of anonymity.

The source said several of those in Stone’s group — three women and another man — were drunk but it was unclear if Stone himself was inebriated.

Video footage of the incident caught by a nearby surveillance camera and released by US media shows Stone fighting off a group of men who scatter when what appears to be a police car arrives at the scene.

A red stain can be seen spreading on Stone’s white shirt.

Another surveillance video released by police shows the two alleged suspects involved in the altercation running and getting into a car that quickly drives off.