In a bear-pit atmosphere on Court Three, the flamboyant 26-year-old fired a backhand winner down the line to seal a 2-6 6-4 4-6 7-6(8) 6-4 win over the 29th-seeded Frenchman and send local fans into delirium.
Bolt's win came shortly after fellow wildcard Alexei Popyrin advanced when seventh seed Dominic Thiem retired with illness when trailing 7-5 6-4 2-0 in their match.
With the nation's number one Alex de Minaur also through, along with top woman Ashleigh Barty and women's wildcard Kimberly Birrell, Australia have five in the third round for the first time since 2003 -- when Lleyton Hewitt was in his pomp and the country was a Davis Cup giant.
A resident of Murray Bridge, a dusty country town in South Australia state, Bolt only came back to tennis in 2016 after finding the "real world" work of building fences and manual labour not to his liking.
"It is unbelievable. My parents have come over from Murray Bridge. Gilles is a top player. It gives me the confidence I can do more,” left-hander Bolt said after a wild celebration, jumping up and down on the court like a Masai warrior and roaring at the terraces.
Having upset American wildcard Jack Sock in his opener, Bolt played fearlessly against former world number six Simon, saving four match points in the fourth set tiebreak before capturing the decisive break in the ninth game of the fifth set.
Nineteen-year-old Popyrin, ranked 163rd, was also pinching himself ahead of a clash with 28th-seeded Frenchman Lucas Pouille.
A tall, rangy teenager who models his game on his Argentine idol Juan Martin del Potro, Popyrin secured at least A$155,000 (£86,195) in prize money and said he would put it to good use.
"On travel. Got to keep it in tennis. Yeah, I'm not going to go berserk with the money. Going to keep it on travel," he said.
(Editing by Ed Osmond)
