Merced police say the stabbing happened at a home on Midge near 27th just before 1 a.m. Sunday morning.
Investigators believe Javier Esparza stabbed a 45-year-old man at the home after he heard him fighting with his mother.
The victim was rushed to Memorial North Hospital, where he had to undergo surgery.
Esparza was arrested and is now facing charges for assault with a deadly weapon.