Juan Diaz says he had only seconds to react on Tuesday.
The incident was captured on camera by a witness as others looked on.
"If I didn't grab the scooter, I don't know what would have happened," Diaz said. "He would have killed me right there."
The vendor is bedridden after being stabbed at least six times.
"When I noticed he already had the blade in his hand," Diaz said. "I wasn't thinking about fighting. I had two bouquets of flowers when I hit him in the head with the flowers to defend myself."
One of those stab wounds pierced his chest and came close to his heart.
Diaz said, "He tried to stab me. I think he tried to hit me in the neck or face. I moved my head. That's when he hit me in the chest."
Diaz said he lost a lot of blood but luckily was rushed to a local hospital.
The suspect got away on the scooter.
Diaz's granddaughter, Heidi Diaz, said it's scary to know his attacker is still on the loose.
"It's not fair," she said. "Today was my grandpa. Who knows who's next."
Diaz doesn't know the suspect but remembers him being very aggressive and angry.
He said it's unfair because he was just trying to earn a living and now he can't work.
"I'm not looking for any problems. I'm humbly selling flowers trying to earn money the right way," Diaz said.
The South LA Sheriff's Station said they're investigating but no arrests have been made.
Diaz's family has set up a GoFundMe page to help him with medical expenses as he recovers.