When Libertyville sophomore Maddie Spaulding hit a short turnaround jumper with 1:28 left in the first quarter, Hersey faced it biggest deficit (7 points) of the young season.
But the Wildcats then faced one of Hersey's best surges of the season.
Sparked by back-to-back 3-pointers by Kelly Weyhrich, the Huskies scored 17 unanswered points and never trailed again in a 46-39 triumph in the semifinals of the Bison Classic at Buffalo Grove High School.
The Huskies raised their record to 4-0 while Libertyville stands at 2-2.
Hersey will face Mother McAuley at 2:30 p.m. Saturday in the tourney final.
Weyhrich also had the last bucket of the 17-0 run, a driving layup which made it 20-11 with 5:15 left in the second quarter.
Senior Andrea Cannon's free throw with 4:18 left capped the 17-0 rally that ended when Wildcats senior forward Claire Keefe hit a pair of free throws en route to her game-high 21 points.
Weyhrich, a 5-foot-4 senior guard, led Hersey with 12 points.
"We started picking it up on defense," said Weyhrich about the Huskies' comeback. "I didn't even realize we did that (17 unanswered points). Our defense just gave us momentum to get the offense going."
The Huskies' offense needed the momentum because Hersey shot 28 percent, well under its average of closer to 40 percent.
"I felt like we got the shots the whole game," said Hersey coach Mary Fendley. "We just had a hard time hitting them. When we went on that run, I thought our shooting might be back. But then we went back to having a hard time making them again."
The Huskies did make them when they had to in the final quarter.
Libertyville kept things interesting but could never get closer than 5 points.
Erin McGrath took a pass from Weyhrich and banked home a jumper for a 37-29 lead with 4:38 left in the game.
Moments later. McGrath's 3-point play made it 40-31.
Maggie O'Sullivan's 3-pointer got Libertyville back to within 6 points.
But senior Gina Miklasz extended the lead again when she drove for a bank shot with 3:11 left.
Earlier in the quarter, junior Maesyn Benjamin hit a key free throw. Cannon made two big ones for a 44-37 lead with 22.7 seconds let after the Wildcats had missed two 3-point attempts.
Keefe rebounded her own miss and put it back to cut the lead to 44-39 with 10.2 seconds left.
But Carly Cooper sealed the verdict with a pair of free throws with 2.3 seconds left.
"Every time they got to within about 6 points, we had someone step up with a big basket," Fendley said.
"It's the little things that make the difference and everyone contributed," said Weyhrich, who also handed out 3 assists. "It was awesome. Everyone did their job."
Junior Erin McGrath did her job on offense and defense, scoring 11 points with 12 rebounds (7 offensive).
Teammate Claire Gritt grabbed 8 rebounds with her 6 points and 3 assists while Miklasz and 7 points and Cooper 4.
Keefe scored 5 of Libertyville's 6 baskets in the middle quarters. The 6-foot forward also grabbed 10 rebounds.
"She's a really good player," said Wildcats coach Greg Pedersen. "If teams try to focus on her, we have other players who can score points, Hopefully it's a pick your poison situation all season."
Senior Caroline Frea added 6 points and 8 rebounds for the Wildcats while teammates Morgan Manski and O'Sullivan hit 3-pointers.
"Hersey is really great and well coached," Pedersen said. "While we're not a happy with a loss, this was good experience for moving forward."
The big run included Hersey forcing three straight turnovers off its press in the first two minutes of the second quarter. Twice the Huskies capitalized with buckets from Weyhrich and Miklasz.
"They're a really great team," Pedersen added. "In order to be competitive with them, we thought we had to to get off to a good start, and we did."