The victim flagged down a passerby on Ocean Street about 10:45 p.m., saying he had been stabbed, Friend said.
The victim told police that a man he knew stabbed him after the two argued at a campsite where they were staying, according to Friend.
Police arrested Steven Dale Goodwin at the campsite, on suspicion of assault with a deadly weapon.
Goodwin, 58, denied the attack, but had blood on his clothes and hands, Friend said.
Santa Cruz police ask anyone with information to call the anonymous tip line at 420-5995 or leave a tip at www.santacruzpolice.com.