The "Gladiator" star bought into South Sydney Rabbitohs in 2006 and over the years has helped lured some of rugby's best players, helping turn the club around.
But they were out-muscled by the Penrith Panthers, who claimed only their third premiership, having also won in 1991 and 2003.
It was just reward for a team that lost last year's final to Melbourne Storm as they dominated territory and possession at a packed Suncorp Stadium in Brisbane.
"It feels like a dream, we have been working so long to get to this point. I've been dreaming of this moment my whole life and it's finally here," said Panthers co-captain Nathan Cleary.
"Losing a grand final last year is a different kind of hurt, you can't describe it, and that's what makes this so much more special. We came back and did it the hard way."
The season-ending decider took place outside Sydney for the first time since 1908 due to the coronavirus pandemic.
With the city in lockdown as it battles an outbreak of the Delta variant, the National Rugby League moved the entire 16-team competition to Queensland state in mid-July.
Despite both teams being from the Sydney the atmosphere in the stadium was electric, with the 39,000-strong crowd in full voice.
The Panthers applied all the early pressure but it took them until the 17th minute for Matt Burton to surge into a gap created by a defensive error and dot down, with Cleary adding the extras.
The lapse fired up the Souths and it was level pegging four minutes later when powerhouse Cody Walker threw a dummy and brushed off four defenders in a weaving sprint to the line.
Adam Reynolds slotted the conversion, but another two points from Cleary off the tee took the Panthers to the break with an 8-6 lead.
Reynolds evened up the scores soon after the restart and it stayed that way for another 22 minutes as the Souths soaked up intense pressure.
But they finally made a mistake, with Stephen Crichton intercepting a loose pass from Walker and sprinting unchallenged to the line.
Cleary converted for 14-8 and the Souths looked beaten, but against the run of play Alex Johnston pulled a try back.
It left Reynolds with a conversion to level the scores with five minutes left, but he pulled it wide and there were no more chances.
