Cheered on by a large crowd, the Slovak Republic survived a strong second-half rally to defeat the Czech Republic 76-72.
The hosts led by as many as 15, 51-36, early in the third quarter, but the visitors kept clawing their way back and eventually took a 69-68 lead - their only of the second half.
However, as if spurred on by the crowd's loud roars, it was the home players who came up with the big plays down the stretch.
Pavla Svrdlikova put the Czech Republic ahead with 5:28 left in the game, but the hosts didn't panic and were quickly back on top as Veronika Cernakova - who topscored with 23 points - made a key steal and converted it with a lay-up that saw the Slovak Republic back in front 71-69.
All subsequent points came from the free-throw line, with none more important than the pair hit by Klaudia Lukacovicova hit with 36 seconds left for the final scoreline. She went on to finish with 20 points and 12 rebounds.
"This is a very important win for us", said head coach Michal Porubcan afterwards. "You always want to start a tournament like this on a positive note, with a win. You don't want to have to play catch-up."
And Porubcan was keen to stress that this was one everybody looked forward to - not just the fans.
"There is a rivalry between the Czech Republic and us in every sport and it's a good thing. We like playing them and it's never easy. We started well in the first half and I think our key players got tired after the break. But we survived."
The hosts got off to a good start and took a 24-19 lead at the end of the first quarter behind the strong play of Lukacovicova.
Cernakova took over the scoring duties in the second quarter to help build a double digit lead, which they held on to going into the break up 47-36.
It looked as though the win was all but wrapped up when they bumped their lead up to 15, 51-36 on a Lukacovicova lay-up.
But the Czech Republic outscored them 20-11 the rest of the third quarter - including a personal 7-0 run by Michaela Stata - to trail by just six, 62-56, at the end of the third period.
The visitors kept plugging away in the final quarter and came within one several times before jumping in front on Svrdlikova's shot.
That was as close as they would get to a win as they failed to get to the key loose balls down the stretch.
Katerina Bartonova led the way for the Czech Republic with 13 points.