Making its first largest-school regional semifinal appearance since the last year of the girls Class AA volleyball state tournament, Rosary desperately sought to force a third set against Waubonsie Valley.
But on three separate occasions with a 1-point lead and serving honors, Rosary servers had their bids hit the net and fall harmlessly to the floor.
The Warriors made the Royals pay as Rachel Minarick and Katie Campbell collaborated on a pair of critical points down the stretch.
With its 25-22, 25-23 victory over the Royals, host Waubonsie Valley advanced to its Class 4A final Thursday to face top-seeded West Aurora, which denied a determined Metea Valley squad 25-23, 25-19, in the opening match of the all-Aurora field.
Rosary had its season conclude at 23-13.
Minarick, who led both teams with 9 kills, including the game-winner in the opener, broke the final of 13 second-game ties after the last of the Royals' three serving gaffes at 23-22.
Match point soon beckoned with another Rosary hitting error, but Briana Flagg, who was equally brilliant all night in her final match for the Royals, had the last of her 8 kills with a savage cross-court spike.
With Rosary trying to force overtime, though, Minarick sent a blazing kill attempt over the Royals' net.
The ball was dug by Rosary, but Campbell rose over the net as the ball came meekly toward the Warriors' side.
The junior middle hammered home the match-clinching point for Waubonsie Valley.
"I knew Rachel was going to hit it hard," Campbell said. "I had to take my time and time it right. We knew we had to come out and play our best."
The Warriors (20-16) avenged a regular-season tournament loss at Wheaton Warrenville South to the Royals to extend their campaign.
On a night when balance was a key for Waubonsie Valley, Minarick seemed to make pivotal plays on a consistent basis for the Warriors.
"We came out and we were ready to play," Minarick said of the Warriors never trailing by more than 3 points in either game. "We knew what we wanted to do. I really thought we kept our composure."
The coaches came away with similar viewpoints.
"Volleyball is a game of momentum," Waubonsie Valley coach Kristen Stuart said.
First-year Rosary coach Rachel Hartmann was left wondering about the golden opportunities the Royals surrendered on serve-receive.
"It was very frustrating," Hartmann said of the central sequence down the stretch. "That was 3 points (lost on service errors) that we could have scored. (The errors) changed the momentum. We couldn't get the momentum back after that."
Marissa Prochaska added 8 kills for Rosary, which also received a match-high 21 assists from Jo Gallagher.
Serving also proved to be the difference for West Aurora (31-5), which completely altered its match with Metea Valley from its service baseline.
The Blackhawks had 9 aces to the Mustangs' lone winner in reversing early deficits in both games.
"We were in that match the whole time," Metea Valley coach Janine Wange said. "(West Aurora senior Lauren Carlini) is an awesome server. I have never seen anyone like her. The stretch of serves took us out of (the match)."
Carlini, the Blackhawks' Wisconsin-bound No. 1 ranked senior in the nation, and Abriya Zeitz keyed critical service runs in both games with a combined 7 aces.
"We're the No. 1 seed, so we're the team to beat," Carlini said.
Katherine Gilmore had 6 kills for Metea Valley, which also received a combined 10 more from Lexie Lobdell and Samantha Kurbyun.