Having spent an enormous amount of physical and emotional energy in their 3-2 quarterfinal loss against Finland on Thursday, the Czechs immediately put the game out of reach.
"It was exciting," Sapovalivova said. "I am really happy because my defenseman passed me a very good pass. I shot and it was a goal."
Natalie Brichova doubled the lead just 21 seconds later and Barbora Proskova extended it to 3-0 with her first of the afternoon at 1:07.
"It was really important," Czechia forward Tereza Plosova said. "We wanted it like this. It gave us the confidence for the rest of the game."
For most of the tournament Czechia coach Dusan Andrasovsky said he was concerned his team had not found its power after most of the team battled illness before the tournament. They found it very quickly on Saturday.
"It's amazing. We were so surprised," Czechia coach Dusan Andrasovsky said. "I was very proud of them. They came here like professional athletes and wanted to win the game for the Czech Republic."
Czechia's opening goal is the fastest scored from the start of a game in U18 Women's World Championship history, beating the tally by Canada's Brigette Lacquette 17 seconds into a contest against Czechia in 2009.
It also topped marks set in Olympic and Women's World Championship history, both 13 seconds. Finland's Mari Pehkonen achieved the feat at the 2006 Olympics vs. the United States. Germany's Maren Valenti did it at the 1994 Women's Worlds against the Swiss.
On the other side, the Slovaks wanted to finish with pride.
"We said to each other, it is our last game," Slovakia captain Zuzana Dobiasova said. "We need to move on and keep going."
Nela Lopusanova closed out her first international tournament with two more highlight-reel goals.
After taking a pass from Emma Tothova in the neutral zone, Lopusanova slid the puck behind Czechia defender Anna Vanickova on the outside and cut inside to give herself a partial breakaway. Goalie Barbora Dalecka made the initial save, but as the rebound popped in the air, Lopusanova gently tapped it in with the heel of her stick.
The 14-year-old then made it 6-2 by scoring breakaway with a between-the-legs shot, putting the puck in the top, far corner at 14:03.
Tatiana Blichova scored for Slovakia 20 seconds later.
Lopusanova finishes the event with 12 points (nine goals, three assists) in her international debut. With the semifinals and medal games yet to be played, Lopusanova holds a five-point advantage over Canada's Caitlin Kraemer (six goals, one assist) and the United States' Margaret Scannell (four goals, three assists).
Proskova scored again 13:01 into the second period to make it 5-1.
Dalecka finished with 16 saves and Anezka Cabelova had two assists in the win.
Slovakian goaltender Sona Kubaniova made her international debut, entering in relief for Livia Debnarova 8:47 into the first period. Debnarova finished with five saves.
Czechia is now 5-0 all-time in its series against Slovakia at the U18 level, but the teams continued tradition by singing and dancing together in the locker room hallways.
"They are our friends," Sapovalivova said. "In a game, it’s a battle. But they are our friends."
Lopusanova, Dobiasova and Blichova earned awards as the top players for Slovakia in the tournament. For the Czechs, it was forwards Barbora Jurickova and Linda Vocetkova, and defender Beata Narovcova who earned honors.
Both teams finished ranked where they entered the tournament; the Czechs in fifth place, the Slovaks in sixth. Both see a very bright future.
"I believe next year we will win the quarterfinal and win a medal," Sapovalivova said.
"It's the end, but we keep smiling and that's a good thing," said Dobiasova. "A lot of girls had great experiences on the ice and they need to keep working. This top division is so hard. I'm so proud of the girls and for the team."