The woman rammed their vehicle with her SUV. Police say one of the suspects shot the woman, and the two men took off running.
The victim's neighbor, who asked not to be identified, was driving by at the time and saw the woman.
"And she said help me please, call 911," he said, "I saw these two guys coming out of the driveway, running out. I called 911, I turned my truck around and followed them."
The neighbor chased after the suspects, keeping contact with authorities the whole time. Police were then able to intercept one of the suspects and make the arrest, but they say they don't recommend taking the law into your own hands.
"It's not something we recommend, usually the best thing is to call," said Lt. John Dewar of the Pasadena Police Department. "But these neighbors were heroes."
The second suspect in the incident was arrested Wednesday night.
The victim was taken to the hospital to be treated for her injuries, but was later released.