Simmons cracked eight fours and eight sixes on the way to his 39-ball ton, easily eclipsing the previous record of 44 balls set by Melbourne Stars blaster Luke Wright in 2012.
The blistering knock of 102 lifted Perth to 7-203, and the Strikers were in the hunt for an upset win after quick-fire knocks from Phil Hughes (58), Alex Hales (31), Nathan Reardon (30) and Jono Dean (29).
The Strikers needed 17 runs for victory off the last over - bowled by Pakistan paceman Yasir Arafat.
That equation became six off the final ball after Tim Ludeman cracked two boundaries.
But Ludeman couldn't land the winning blow, scuffing Arafat's straight full toss to square leg as Adelaide finished at 6-198 in front of a sell-out crowd of 19,495.
The win guaranteed the Scorchers (5-2) a spot in this summer's finals, but Adelaide need to win their last two games if they are to join Perth in the top-four.
Returning paceman Pat Cummins snared 1-40 from his four overs in his Scorchers debut.
The 20-year-old, on the comeback trail from his latest bout of back stress fractures, regularly bowled around 140km/h against the wind in a solid hit-out.
The spotlight was firmly on Cummins following two years of injury problems.
But it was Simmons who well and truly stole the show.
the 31-year-old entered Thursday's match under the pump after producing scores of 9. 8 and 0 in his previous three innings.
Simmons didn't look all that convincing early, and he was lucky to survive on 11 when a running Jon Holland misjudged a skied strike and failed to get his hands on the ball.
But from there he exploded, hitting a series of boundaries to repay the faith shown in him by coach Justin Langer.
"I wasn't really sure if I was going to play this game. So credit to the Scorchers for sticking with me. JL has been very good for me," Simmons said.
Langer said Simmons' confidence in himself convinced him to keep selecting him.
"He kept telling me he just needed a few runs under his belt and then he would be right," Langer said.
"It's great to give a guy an opportunity."
Wright congratulated Simmons on snaring the record, but declared he would try to win it back.
"That was one of the most enjoyable games I've ever played," Cummins said.
"It's great fun to be back out there.
"There were a couple of balls that let me down. But other than that, I was pretty happy with how I went."