The 24-year-old, who comes from Annan and trains in Newcastle, won the 200m butterfly earlier in the week and he added the 100m event yesterday in a time of 53.79. Cameron Brodie (Kelly College) was a distant second in 55.55.
Mayor's time was just outside the Games nomination time, but he hopes the selectors might look kindly upon the situation and allow him to take part in both distances in New Delhi in October.
"I would love to get to swim twice at my first games," said Mayor. "But I'll respect whatever decision they make. I'm just delighted to get the chance to swim for Scotland.
"I was just 0.1 off the time I needed to make the Melbourne Games four years ago. It was so tough at the time, but that's sport. This year has been really good and I always love coming to Tollcross. It's a great venue with great crowds."
Last year, Mayor moved from Newcastle to Nottingham to train alongside his then girlfriend – double Olympic Champion Rebecca Adlington – at the Nova centurion Club.
"I struggled a bit and it's good to be back with my long time coach, Ian Oliver, in Newcastle. I started with him back in 2004 when I started to take the sport seriously."
Having now achieved his Commonwealth Games goal, Mayor tentatively looks forward to taking another step and making the 2012 Olympics in London.
"That would be a dream," he admitted. "But things can happen from week to week. At the moment, I'm just having fun and looking forward to swimming for Scotland in Delhi."
Edinburgh University's Kerry Buchan, who swam in the 2006 Games, was another to claim a victory double. With the 200m breaststroke gold already in the bag, she won the 100m in 1:10.21. The 23-year-old was involved in a car crash just a week before the 2008 Olympic trials and missed out on a trip to Beijing.
"I was so disappointed to miss out on the Olympics that I quit swimming for three months," she said. "I came back and then had some illnesses.
"But I moved from Aberdeen to Edinburgh last September and I'm now training with Chris Jones and it's working out really well. My first Commonwealth Games in Australia were great, but I think Delhi will be very different. Hopefully, it will just be as good."
Hannah Miley, Scotland's great all-rounder, claimed a second gold in the 200m backstroke – then said she had just done it for fun.
The 20-year-old, who is coached by her father, Patrick, at the Garioch Pool in Inverurie, has her sights set on individual medley medals in Delhi.
Emma Hunter of East Lothian broke the Scottish record in the heats of the 50m backstroke and she did it again with a time of 29secs in finishing second in the final.