Coming top in the first session means that Tongwynlais Temperance Band are now in contention for the final grand prize of £10,000 which will be announced in the series finale.
As well as competing for the prestige and the prize, drumming up interest was the aim for Tongwynlais Percussionist and Treasurer Jason Bevan.
"Brass bands are close knit communities who tend to celebrate among themselves and the public rarely get the chance to experience them in their full glory.
"They might hear them in the park or at a march, but they won't see them doing high-end stuff," explains Jason.
"We tried to choose a varied programme which was appealing to all kinds of music – we opened with a jazz number, followed by a piece by Karl Jenkins which is more typical of a traditional brass band.
"We also had Scottish and Russian pieces. We wanted to appeal to the widest possible audience," says Jason.
The win is the latest in a string of recent successes for the band, who are currently 11th in the Brass Band World Rankings.
"It's a good time to be in the band," says Jason. "We've had our ups and downs, but we're currently at the highest ranking that we've been for a while. And to have this win too, it's fantastic."