"If the Stars lose from here, I don't think they'll ever win it," he said. "It was the unlosable game."
Young Renegades wicketkeeper Sam Harper was stunned on the field.
"The atmosphere out here is incredible now – unbelieveable," Harper said.
"I can't believe what's happen here in the last 20 minutes," Warne said.
After the match, Warne said the Stars would be shattered.
"For those men in red, they'll sit there and giggle and say 'I can't believe we won the Big Bash Final'," Warne said.
"For the men in green, they've got some serious questions they've got to ask themselves. They lost the game through reckless cricket, maybe a bit complacent and some pretty ordinary shots and they'll be a shattered group."
Social media was stunned by the incredible result.
The Stars were easing towards a win before the match turned on a dime and the Renegades defended a modest total of 5/145.
Renegades had never made a final and have now tasted a stunning victory.
The Renegades had struggled to a competitive score thanks to Dan Christian and Tom Cooper combining for a stunning 80-run fifth wicket partnership to save the Melbourne Renegades.
The home side was 5/65 after tight bowling early and a bit of luck with Adam Zampa taking 2/21 and Jackson Bird nabbing 2/25.
The run out of Aaron Finch was the big wicket with a glance of Bird's boot ricocheting onto the stumps.
Finch is normally good at hiding his emotions and stayed calm as he walked off the field.
But as he got to the tunnel, Finch took out his frustrations on a chair, demolishing it with his bat.
The Renegades were 3/47 at the end of the power play and then 5/65 after Adam Zampa struck.
With hope nearly gone, Cooper and Christian resurrected the innings with some late order hitting.
Copper smoked two sixes to get to 43 from 35 balls, while Christian again hit an important 38 off 30 balls to get the Renegades to 5/145 from its 20 overs.
Christian also took 2/33 from four overs to give him seven tournament wins around the world to win man of the match.
"This is right up there, it's easy to say it's the best one, let's say it's the best one, it feels pretty special," Christian said.
It gave the Renegades something to bowl to and makes it an intriguing second innings.
The Stars' openers took their time with Ben Dunk and Marcus Stoinis in no hurry.
The pair cruised to a-run-a-ball 36 off the power play and only passing 60 in the ninth over with a crushing six from Stoinis.
But all of a sudden the match flipped and gave the Renegades a famous victory.
Glenn Maxwell cast an disappointed
"I am really proud, we've played some great cricket this tournament and to fall just short at the end is really disappointing," Maxwell said. "There are a lot of great signs coming out of this group and going forward for next year."