With one final play, the Panthers zigged and zagged within their own half, but the Storm defence held firm to take another historic grand final victory.
Earlier, the Panthers had been left dead in the water a the Storm ran out to a 26-0 lead early in the second half.
The Panthers scored the last four tries of the match after a series of controversial calls went against the Storm.
The first allowed Isaah Yeo to set up a try after running around his own teammate in a clear obstruction.
The second saw halfback Jahrome Hughes sent to the sin bin with nine minutes left on the clock after the NRL Bunker ruled he had performed a professional foul by taking out Villiame Kikau.
With the Storm reduced to 12 - and then 11 - men at the death, the Panthers very nearly pinched it.
But the Storm showed their class to endure the onslaught and emerge with a famous grand final triumph.
Smith was even left emotional at fulltime as he talked about his team's incredible defence when it mattered the most.
"Jeez, we did it the hard way there, 11 men in the end," Smith said.
"Penrith were coming home with a wet sail and playing the footy they played all year.
"I'm just really proud of this club- not just this football team that played tonight, but the entire squad."
Here's how the extraordinary drama played out: