Austin had 10 birdies and an eagle, which added up to 43 points in the modified Stableford scoring format.
The event features a pro side consisting of 27 PGA Tour Champions players and four LPGA players, and a celebrity side with 47 celebs and athletes.
An eagle is worth six points, birdie worth three points, par worth one point, bogey worth zero, and double bogey or worse worth minus-2.
Austin started with a birdie on the first hole at par-71 Tranquilo Golf Club at Four Seasons Resort in Orlando, Fla. And eagle at the par-5 ninth had him turn in 6-under 30 (22 points). He added another birdie at No. 11 and then birdied five in a row, beginning at the 13th.
"I really never thought about it until I birdied 16," Austin said. "That got me to 11 under and I thought, OK."
Needing a birdie at the last to shoot 58, Austin missed his tee shot on the par-3 18th well right of the green. He chipped up nicely to secure par and 59; though, as he admitted, he wasn’t aware.
"I didn't know it was a par-71 so when I walked off the last green I thought I shot 60," Austin said. "Everybody goes, 'No, it's a par-71.' So, ah, cool."
The round was not shot during an official PGA Tour Champions event as this is considered a Challenge Season event.