Police say the victim and her ex-husband were engaged in a child custody exchange at Buena Vista Street and San Fernando Road when things got heated.
Police say the man was armed with a gun and a knife and stabbed the woman in the stomach. As she got away, some Good Samaritans stepped in and detained the ex-husband.
The woman was hospitalized in stable condition.
The man was also taken to the hospital for head injuries he received while struggling with those Good Samaritans.