The win extended the Scorchers' head-to-head record to 6-0 against the Renegades.
The drama of the final ball reflected that of the final over in its entirety, which opened with the Scorchers needing nine to achieve their victory total of 149 and unfolded with the visitors losing the crucial wickets of Mitch Marsh (34 off 22) and Adam Voges (one from two) in consecutive balls.
The equation to win was three runs from the final ball with Agar on strike, with the fluid all-rounder calmly dispatching an Aaron Finch full-toss over the deep mid-wicket boundary for six.
While the power of youth in Agar and Marsh ensured the Scorchers grabbed the win, it was the poise and maturity of Player of the Match Michael Klinger (72 from 55) that set up the victory.
The Scorchers won the toss and sent the hosts in, restricting them to 8-148, before Klinger played a patient hand in pursuit of the dangerous total, creating poise in the top-order and bringing up his 50 with a six off former Perth fan favourite Brad Hogg.
It was slow going for much of the match, with the Scorchers constantly slipping behind the required run rate, before Klinger and Marsh helped their side recover.
The Renegades appeared set for an imposing total, with former Scorchers opener Marcus Harris and opening partner Aaron Finch nearing the team half-ton without loss.
However, a sharp catch by skipper Adam Voges at cover off the bowling of Andrew Tye dismissed Finch for 24 and that became the tale of the Renegades' innings.
Harris followed for 25, with only Cameron White (37 off 29) managing to exit the 20s safely, while a towering six to West Indian Dwayne Bravo in the dying stages boosted the home side to a challenging, but still modest 8-148.
Bravo was later carried off the field on a stretcher during his side’s fielding innings after sustaining what appeared to be a hamstring injury.
Gloucestershire trio, Klinger, Tye & Bancroft will be in action for the Scorchers on New Year’s Day for their next match against Sydney Thunder.
Watch Klinger in action in the NatWest T20 Blast in 2017 with our One-Day Membership, just £89 with our early-bird price. Click here.
