The Minnesota man who stabbed one teen to death and injured several others in a chaotic water tubing brawl claims he “absolutely” had to use a knife to defend himself against the young group or he would have been killed.

Nicolae Miu, 54, testified Tuesday that he reached for the knife after the rowdy group’s taunts turned physical during the fatal July 30, 2022, attack in Wisconsin’s Apple River that left 17-year-old honor student Isaac Schuman dead.

“I was surrounded, they were yelling, they had just pushed me, and it seemed like they were not backing away,” Miu said on the stand. 

The engineer offered a play-by-play alongside video footage of the frantic moments before he plunged the knife into Schuman’s torso.

Miu — who appeared noticeably thinner than the nearly 2-year-old clip — had allegedly been searching for a friend’s lost phone in the St. Croix County river when the young group accused him of taking pictures and “looking for little girls.” 

The alleged killer said his fear “crept up” as the teens’ shouts and laughs turned into shoving.

In the video, Miu can be seen slowly pulling out a Swiss army knife, which he said he had been carrying to cut rope for the planned water tubing adventure.

“I’m reaching for my pocket knife because, at one point, my fear was getting really high. I was getting ready to pull it up,” Miu said.

Two teenage girls who were with the group were the first to grab Miu, he testified, but the verbal altercation turned into a “horror situation” when one of the boys punched him in the face and pushed him into the water to “drown.”

Miu said he didn’t know how many people were attacking him, but knew it was “more than I could handle.”

Miu said he was “in a fog” for the rest of the incident — which included allegedly plunging the knife into Schuman’s torso and slashing four others.

Schuman was rushed to the hospital, where he was pronounced dead.

Miu admitted on the stand to tossing the knife into the water during the frenzy because he was afraid: “I felt like I had to throw it away.”

When asked by the defense whether he still believes he needed to use the knife against the young group, Miu insisted he would be dead if he hadn’t.

“Absolutely,” Miu said. “I believe I would have been killed that day.”

Miu has long claimed self-defense in the shocking brawl, which he said has left him with persistent nightmares.

In recorded interviews previously played in court, Miu compared the teenagers to “wolves” that were “attacking me from all directions.”

“They came on to me. They hit me, they got on top of me, and I don’t remember anything after that,” he said.

One witness who took the stand earlier in the trial claimed Miu was the one to approach the group. Two others told authorities Miu was the one who turned the altercation physical when he punched a young woman.

Miu has pleaded not guilty to first-degree homicide and attempted first-degree homicide charges.