Jodie and Bianca Williams scampered themselves onto the 200m podium - and vowed to upgrade their silver and bronzes to relay gold.
Jamaica might be the quartet to beat but the sprint youngsters, just 20, are certainly brimming with confidence.
It's hard to think - considering Dina Asher-Smith has just won 100m gold at the World Junior Championships - that Great Britain didn't even qualify a women's sprint relay team for their home Games two years ago.
"It's so nice to come to a championships and run a PB because it means you actually gave your all," said Williams after clocking 22.50 seconds - the joint-second fastest time ever by a Brit over 200m.
"I was battling to the line, gritting my teeth and giving it my all. This is just the start – we beat the Jamaicans which is a massive thing.
“Everyone is so quick to write-off the women’s sprinters but we’ve come out here and started to show we can perform on this stage with a strong field.
"We've got an amazing team, an amazing group of girls. I absolutely can't wait for the relay. We're going to try and take out the Jamaicans, so you've got to watch this space.
“If we all change over well, we can do this. We can definitely do this."
Glasgow poster girl Eilidh Child delivered on her hype to take 400m hurdles silver behind Jamaica's Kaliese Spencer - delighting a partisan crowd at Hampden Park.
"I put down a really good race, I stepped off that track knowing I had given it everything and I'm just delighted to come away with a silver medal.
"I knew if I executed my race right I could come away with a medal, I didn't know which colour.
"I put on a good performance. It was not enough for gold, but I will cherish my silver medal. That's one of my best moments ever."
And Jazmin Sawyers - former silver medallist in bobsleigh at the Winter Youth Olympic Games - took a surprise long jump silver.
"Everyone that knows me has told me to go out and enjoy it, because that’s when I jump my best," she said.
“There’s no point being serious and focused, it doesn’t work for me. I have got to be smiling and bouncing around.
“Every time I found myself too in the zone I told myself to calm down, I looked at the crowd with everyone waving flags and told myself to just have some fun.”
© Sportsbeat 2014