After knocking the Scorchers over for 127 from 19.2 overs at Perth Stadium on Wednesday night, the Renegades almost made a meal of the modest chase before Peake came to their rescue.
With four to win off the last ball, Peake, who headed straight from the ground to the airport bound for Africa where he will captain Australia at the under-19 World Cup, shimmied across in pre-meditated fashion and paddled Aaron Hardie's full delivery over fine leg deep into the stands.
The Renegades' pursuit had looked forlorn in the 17th over when Peake was given out for 15 with a soft signal after Scorchers captain Ashton Turner snared a difficult tumbling catch.
But Peake was reprieved - and subsequently hounded by the parochial Perth crowd - after replays showed the ball touched the ground while in Turner's hand as he somersaulted backwards.
"It's pretty surreal," Peake said.
"To do it here in front of all the Scorchers fans is pretty special and what you grow up dreaming of doing.
"I had a bit of luck and (I'm) just happy that it all paid off tonight."
After Josh Brown (22) teed off early, the 'Gades were cruising at 1-51 from six overs before being restricted to 4-23 from the next eight.
At one stage 50 balls passed without a boundary before Peake dominated a 42-run sixth-wicket stand with skipper Will Sutherland (15) and rode his good fortune to finish his BBL campaign on a stunning high.
Earlier, Gurinder Sandhu snared 4-28 to take his season tally to 14 wickets at 14.71, moving into top position on the Golden Arm leaderboard.
Aaron Hardie (44) was scratchy but top-scored for the Scorchers, who wobbled early and crashed hard late, losing 5-11 from 17 deliveries.
After Finn Allen (8) and Cooper Connolly (3) fell cheaply, Mitch Marsh, who had looked in solid touch, feathered Hassan Ali's arm-ball to Mohammad Rizwan.
Three wickets fell in Sandhu's last over as the Scorchers lost 5-16.
