The visitors established a double-digit lead as early as the first quarter and Rivas never really threatened to get back on level terms against the visitors' balanced attack.
Hana Horakova added 16 points while Taj McWilliams had 14, Eva Viteckova 13 and Jelena Skerovic 10.
Catherine Joens led Rivas with 15 points while Petra Ujhelyi and Anna Cruz added 11 each.
Jan Bobrovsky, Frisco Sika Brno coach:
"The key was our very good defense in the first quarter. Our team fought well and tactically, we played near perfect for 40 minutes. We felt like a united team, taking a lot of rebounds and helping each other. This is an extraordinary achievement. I am proud of my team."
Javier Fort, Rivas Ecopolis coach:
"Congratulations to Brno. It was a game between two very good teams. We lost an important game. But I am proud of my team. Our opponent played long possessions and that was bad for our intensive defense. They made easy points and we lost too many balls."
Clara Bermejo, Rivas Ecopolis player:
"We've lost and I'm very disappointed. Brno is a very difficult team. We made some mistakes that Brno took advantage of. We couldn't find the right rhythm throughout the game."