"He walked across the street and we immediately thought that he was a troubled man," said Melissa.
"We were suspicious about him, so, we were like, 'OK, well, you know, stay calm, don't make eye contact with him," said Emily, a friend who was walking with Melissa when the incident occurred.
The girls only wanted to use their first names for safety purposes while speaking with the media on Monday.
Emily and Melissa were walking home from a bagel shop ahead of Emily's parents on Sunday morning. The girls passed the suspect, 49-year-old David Eddy.
"He turned around suddenly, and [Emily] turned around to look at me," said Melissa.
"And then I saw him with the knife, like, about to lunge into her," said Emily. "And then, we both screamed at the top of our lungs ... like bloody murder."
Melissa suffered two stab wounds to her rib area, underneath her right arm.
"It was so weird; it was like nothing had happened. He just walked away," said Emily.
"When I fell to the floor and I pulled my hand away ... and there was blood on my hand ... they instantly came running to me," said Melissa.
Villa Park is described as having the lowest crime rate in Orange County. A lot of people were nearby at the time. A gas station worker and other Good Samaritans stepped in to help. Residents held Eddy down until authorities arrived.
Eddy is a transient. Authorities say he spent time in at least two psychiatric facilities and has been in trouble with the law most of his life.
"Assault with a deadly weapon, different assaults ... one including an assault on a peace officer," said Jim Amormino, Orange County Sheriff's Department.
Eddy now faces attempted murder charges.
Melissa is thanking everyone who helped. However, Melissa's family is angry the attack happened, given Eddy's background.
"This should have never happened. It's Sunday morning at 11 o'clock in the morning," said Melissa's mother.
"I want him to go to jail. I don't think that he should be able to have the chance to do anything like this again," said Melissa.
Authorities say Eddy had seven cases pending against him prior to the stabbing.