The taxi driver who was nearly slashed to death early Friday outside a Portland strip club said the customer who attacked him had been chatting with him normally moments before the man grabbed him from behind with a knife.

Joe Kamysz was at the intersection of Riverside Street and Larrabee Road, only a few hundred feet from dropping off 30-year-old Justin Kristiansen at PT’s Showclub early Friday, when Kamysz said he heard Kristiansen make an ominous threat from the backseat behind him.

“He just reached around and said, ‘I’m gonna cut you,’ ” said Kamysz, 60, of Gorham. “I was like, ‘Aw crap.’ I’m vulnerable. We were just chitchatting, nothing to lead you to believe somebody was going to be a problem.”

Police said Kristiansen tried to slash Kamysz’s throat before fleeing the cab. Kamysz said he could have been killed, but he lifted his right hand to block the blade.

He suffered deep cuts on his neck and on his right palm, Kamysz said. Police said the attack occurred about 1:41 a.m.

As he pulled into the parking lot of PT’s, Kamysz said Kristiansen was flung across the back seat, stopping the attack. Kamysz immediately approached the club’s bouncers.

“I said, ‘I’ve been cut, I need help,’ ” Kamysz said. One of the staff at the door was an EMT, he said, and helped him slow the bleeding.

Meanwhile, Kristiansen fled the cab.

Westbrook police found him a short distance away. Kristiansen has been charged with elevated aggravated assault, and is expected to make his first appearance Monday at Cumberland County Unified Criminal Court in Portland.

Kamysz was taken to Brigham and Women’s Hospital in Boston for treatment of his wounds and was released Friday afternoon.

Perhaps most mystifying, Kamysz said, is that he had given Kristiansen a ride Thursday night and that nothing seemed amiss.

Police said they, too, have yet to identify a motive.

Police have had contact with Kristiansen before, but Lt. Robert Martin said he could not describe the nature or circumstances of the prior incidents.

Kristiansen, of Portland, has no prior criminal record in Maine, according to the State Bureau of Identification.

Craig Cobbett, who owns 207 Taxi, the company for which Kamysz works, said he was horrified by the attack. Cobbett has already inquired with the city of Portland, which regulates the taxi business, whether he can install dividers between the rear passenger seat and the drivers, which are standard in many cabs in other large cities, he said.

“If they give me the OK, I’ll start on that tomorrow, having those installed,” Cobbett said.

Kristiansen’s quick capture was credited to witnesses who immediately came forward to provide police with an accurate description of the suspect and where he was last seen, Martin said. Maine State Police assisted with the incident.

Anyone with information related to the assault is asked to call the Portland Police Department at 874-8575.