Davis denied Scott on the third extra hole at Springhead Country Club in Ohio, potentially snapping the former world No.1's streak of 91 majors stretching back to the 2001 US Open.
To put his remarkable longevity in perspective, Scott's unbroken sequence is more than double that of the next longest run among active players – Jordan Spieth's 44.
Tiger Woods's record is 46 in a row.
After surging past Tom Watson last year, Scott's streak is second only to Jack Nicklaus's 146 without missing a major between 1962 and 1998.
But now the 2013 Masters champion must rely on the golf gods to earn a start at Pinehurst for the upcoming US Open from June 13-16.
The 43-year-old can still make the 156-man field if he keeps his place in the world's top 60 as of next Monday.
He's currently ranked right on the cut-off at world No.60 but could fall back given he's not playing this week's Memorial PGA Tour event.
At the very least Scott will be an alternate for a late call-up, while the USGA could also offer him an exemption.
UNBELIEVABLE PLAYOFF DRAMA!— U.S. Open (@usopengolf) Adam Scott chips in and Cam Davis shows nerves of steel by rolling a birdie right behind him! pic.twitter.com/6MqYheJG5pJune 4, 2024
Davis, who held his nerve to birdie the first playoff hole after Scott had chipped in to seemingly win through, said he wasn't aware of Scott's streak.
"I don't think I would have tried any less but it just goes to show how good a player he is," Davis said.
"I had to hit a cracking shot into this hole here to get on top of him.
"He's been an idol of mine so it's been great golf against him.
"So all the best to him. I hope he finds a way in. He's right on the bubble world ranking wise so fingers crossed we can both be there."
While Scott's position is uncertain, Davis - who tied for 12th at the Masters before missing the cut at the PGA Championship - gives Australia at least four in the field for the season's third major.
He joins Cameron Smith, Jason Day and Min Woo Lee.
Among others to survive Monday (Tuesday AEST) qualifying - often dubbed "golf's longest day" - were one-time world No.4 Matt Kuchar and fellow American Webb Simpson, the 2012 champion.
