The two exchanged punches for about 30 seconds. The clerk then grabbed a knife and lunged at the robber.
The suspect eventually dropped the cash and took off. The store owner called the clerk a hero.
"This kid, weighing maybe 150 pounds, jumps up, I mean he put his hands up like Oscar De La Hoya and he went at this guy and, I mean, it was on," said owner Tim Ryan.
The robber then led police on a high-speed chase after carjacking a cab driver. During the pursuit, the stolen taxi clipped a school bus and crashed into a pole.
The suspect tried to run but was quickly caught and arrested by police.