The three-time Australian PGA champion and dual Australian Open winner collected 12 birdies in his record-setting second round at the Moama Masters on Friday.
Lonard would have posted a 58 had he not bogeyed his final hole, the par-3 ninth, after finding a greenside bunker at Rich River Golf Club's East Course on the NSW-Victoria border.
He needed to hole a bogey putt from just inside two metres to break the magical 60 barrier and became the first player to do so on Australia's PGA Legends Tour.
"I was very happy to see that last putt go in," Lonard said after opening with a 73 on Thursday before pulling off a one-shot win over John Onions (70-63).
"It was a bit of a day today. Yesterday I was never playing again, giving up golf and getting a job, and today all of a sudden I'm back, I love the game and everything's happy.
"It's a funny game. Sometimes it gives it to you and sometimes it doesn't."
The 56-year-old has gone close to carding a 59 before.
"I've had a couple of other goes at it," Lonard said.
"I parred the last in Sao Paulo years ago for a 60 and at the Jack Newton Classic at Twin Waters I missed a putt for a 59.
"I didn't think I'd get another chance of doing it. It's a nice little thing to happen towards the end of my career I suppose."
Lonard finished at eight under for the two-round event, with Onions seven under.
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