Jill Bennett had been acting head teacher at Priory Primary School in Dudley for a few days before it was put into special measures.
In July 2012, inspectors saw a pupil assaulting a teaching assistant who tried to stop a fight.
The watchdog's inspector Helen Morrison said it was "the worst school she had seen", said current head Ms Bennett.
It was then rated inadequate in all four areas assessed by Ofsted.
The watchdog said at the time there was:
Earlier, the school released its latest inspection, which deems it good in all four areas assessed.
Ms Bennett said her motivation to reverse the school's fortunes came because she attended it herself as a child, as did her sisters Glenda and Andrea, and Ms Bennett's own two children, Alex and Megan.
She said: "The area has always been deprived, but I asked myself, 'why couldn't Priory children have good opportunities?
"I told pupils, I was a good student myself, never an A* student, but I was always determined and that's what we would be."
A school an Ofsted inspector once dubbed "the worst she had seen" is now rated good.