The record 58 will take some beating in the history of the club that celebrated its centenary in 2014.
It is Toomey's second score of 58 after he set an unofficial record at the Hamilton Golf Club.
"I started birdie, birdie from number seven and then made a really good up and down on the par-3 number nine," he said.
"I drove it on the 10th green and holed a 12 footer for eagle and the momentum just kept going from there really.
"Honestly it was not like I was striping it down every fairway and hitting it to within a foot on every hole.
"It was just really solid and I finally had a day when my putter got really hot so it was good."