A Santa Rosa man was in stable condition Friday after being stabbed during an altercation in Old Courthouse Square downtown, authorities said.

Loren Hackett, 24 - whom friends at the scene called Paul - was stabbed once in the neck Thursday night and underwent surgery at Santa Rosa Memorial Hospital.

Leland Pinola Jr., 33, was identified Friday as the suspected assailant. He was being held without bail in Sonoma County Jail on suspicion of attempted murder and battery causing serious bodily injury.

The attack happened when Hackett confronted Pinola about an incident earlier Thursday in which Pinola allegedly hit Hackett's girlfriend, Santa Rosa Police Lt. Ed Hemphill said.

The 10 p.m. attack took place on the west side of Old Courthouse Square.

Pinola was arrested minutes later near Sonoma Avenue and D Street. Witnesses identified him as the assailant, police said.