Two boys are in hospital after a fight broke out in Sydney's west.
Paramedic Penelope Little said two teenagers were seriously injured in the attack on Popondetta Road at Blackett.
"The first patient was an 18-year-old male who sustained two stab wounds to his upper chest and one to the neck.
"He was taken by paramedics to Nepean hospital and he is in a serious but stable condition."
The other boy who was also injured is believed to have a head injury.
The offender was arrested at the scene.