Scott made his ace in the Turkish Airlines Challenge at Samsun Golf Club in Atakum, holing an 8-iron at the 196-yard 13th hole on the Black Sea coast.
A couple of hours later, John also holed out with a 9-iron at the 171-yard tenth at Ladybank playing in an event on the Big Johnsons Tour, the domestic circuit he runs.
“What are the odds on that?” said Scott, the eldest of the Clydebank pair, in giving his reaction to the memorable family feat.
“When John messaged me to say he he’d had also had one, I thought he was joking, but, of course, he wasn’t. It was very strange that we both had a hole-in-one on the same day.”
John, who made his ace in the company of Paul Lawrie, added: “I already knew about Scott’s hole-in-one when I arrived at Ladybank as Mikey Stewart told me as I was ordering my breakfast and for me to then go out and get one as well is pretty unbelievable.
“I was more chuffed about Scott’s hole-in-one, to be honest, as it helped him shoot seven-under and here’s hoping we will be saying ‘cheers’ to him on Sunday night with a trophy in his hands.”
Helped by his ace - sandwiched by two birdies - Scott sits five off the lead in joint-10th at halfway in the Turkish event, with compatriot Connor Syme a shot ahead of him after he backed up an opening 65 with an equally impressive 67.
It was a proud day for mum Marion, who said: “I’m happy for the boys. Also, my daughter Allana is in Florida with her hip hop team representing Scotland and they came fourth in the world yesterday.”