An argument possibly over $5 ended with one man cutting another with a knife on Butler’s south side Tuesday afternoon, city police said.

Scott H. Fosnaught, 54, who has no known address, is charged with felony assault. He is in the Butler County Prison on $100,000 bail.

Police suspect Fosnaught attacked Mark Graham shortly after 2:30 p.m. in the Clay Hills area between South Monroe and Kittanning streets. Fosnaught claimed he acted in self defense.

Graham, 51, of Butler was treated at a Pittsburgh hospital for a one-inch deep knife wound to his stomach. His condition was not known this morning.

Police were called after a man found the bleeding victim near Clay Hills.

Graham’s injury was described as a 10-inch cut that stretched from the center of his abdomen to his left side across the oblique muscle, according to court documents.

He was taken to Butler Memorial Hospital.

Graham told investigators that he had confronted Fosnaught over a $5 debt. But Fosnaught denied owing the victim any money, prompting an argument.

Moments later Fosnaught had a knife and threatened to stab Graham. In turn, Graham recounted, he struck Fosnaught in the face, twice. That’s when Fosnaught allegedly cut Graham and ran.

Police about 4:20 p.m. found Fosnaught at the Grapevine Center parking lot on North Elm Street. He did not have the knife and claimed he threw it in the woods. Police have not found the knife.

Investigators asked Fosnaught if he cut Graham. “He stated that he defended himself,” Capt. David Dalcamo said in an affidavit.