Sporting Team Renicks T-shirts, Thomas and Agnes were among a jubillant home crowd who watched their girls take gold, one after the other, on the opening day of the Commonwealth Games at the SECC.
Kimberley, 26, secured Scotland's first gold in the under 48kg judo category. Just an hour later, sister Louise, 31, followed her lead, winning the under 52kg.
Speaking from the family home in Glendale Grove, Coatbridge, Thomas, 51, said they were still coming to terms with the double triumph.
He said: "It was brilliant!
"All our feet were stamping. We were shouting and screaming when it finished. Even though they are all there as a team, they are also individuals at the end of the day.
"It will take a couple of days for it to sink in."
The sisters are following a family tradition after their father took up the sport when he was 14.
He coached them when they attended the Kanokwai judo club at Kirkshaws primary, where they both went to school, before moving up to Rosehall High School in Coatbridge.
He said: "Kimberley was four and a half when she started.
"Louise was in the Brownies then, when she was about 10, she asked to come to judo. Kimberley was there all the time and Louise would come on and off the mat. They progressed through the local competitions and got through to bigger championships.
"I just tried to treat them the same as everyone else but I probably was tougher on them than some of the other kids. You just try and encourage them, as long as that's what they want to do."
Son Thomas, now 30, also took up the sport, becoming Scottish champion, his dad said, until he gave it up when he was 15.
"He doesn't regret giving it up. He was there with his wife Lauren to see them win on Thursday night".
Mum Agnes, who was diagnosed with brain atrophy three years ago, said the sisters fitted their training in around helping her.
She has mobility and balance problems, and also struggles to speak sometimes when she is tired.
She said: "They have been good helping me. I'm not in pain, I just feel tired all the time but I'm a fighter."
Her tiredness contributed to the couple leaving the SECC after the girls' double win without staying late for the celebrations but they hope to catch up with them early next week.
Thomas, who still coaches at Kanokwai during term time, said: "They're on the phone every day, when they can. They're elated."
He declined to be drawn on whether one of the sisters was better than the other. He said: "I've got to be impartial.
"Louise will say she's better. At one point they were fighting at the same weight and, at those meets, Louise was winning all the matches. It was working against them so Kimberley decided to move down a weight."
He said the sisters still train together, at the Edinburgh judo centre in Ratho, and help out at the club where they started.
He added: "With Kimberley on first, it put a bit of pressure on Louise. She saw her get a gold and she had to get one!
"We were confident they would get a medal, they're at that stage. They were all geared up for a win".