It appeared Roncalli was headed toward its 35th straight victory, dating back to last season.
The Jets, who came into Thursday's WIAA Division 4 state semi-final game with New Glarus with a 26-0 record and the 2018 Division 4 Gold Ball secured away in the school's trophy case, had taken 27-21 lead with 4:44 left in the first half on a layup by senior Ian Behringer.
The game's momentum and the quickness edge definitely were in the Jets' favor.
But New Glarus then opted to switch from a man-to-man defense to an aggressive 2-3 zone, and that made all the difference in the Glarner Knights' 44-41 victory.
New Glarus got 21 points, 5 rebounds and 4 assists from senior point guard Jaden Kreklow, 13 points and some timely three-point baskets from senior wing guard Zach Feller, and used its exceptionally effective zone defense to hold Roncalli to 14 points over the final 20 minutes of the game while winning its 25th game in 27 outings this season.
"I thought our defense was as good as it's been all year," New Glarus coach Travis Sysko said. "It was a gritty effort to hold a team like Roncalli to just 41 points."
Roncalli never led in the second half, but the Jets managed to tie the game at 41 with 2:58 left on a Behringer layup.
After a stop on the other end, Roncalli senior Chombi Lambert (5-10) missed a three-point attempt.
Kreklow scored on a putback to make it 43-41 with 1:11 remaining. Roncalli's Matt LeVene (6-1) then missed a perimeter jumper and Kreklow converted 1 of 2 charity tosses on the other end.
Lambert missed a three-point try with :10 left, but sophomore Mason Martinson (6-4) missed the front end of a bonus free throw, giving Roncalli one last chance to tie it up.
However, Levene and Dan Burgarino each missed deep three-point shots and New Glarus walked off the Kohl Center floor with the win.
"We knew we could play with these guys if we played up to our potential," Sysko said. "We just knew we could run with those guys and we did."
Roncalli, which crushed a very good Milwaukee Academy of Science squad 81-53 in the sectional final, fell to 2-7 in state-tournament appearances, including last year's 2-0 run that featured a state-title game triumph over Marathon.
"New Glarus played really well," Roncalli coach Joe Garceau said. "They made more plays down the stretch. We had a heck of a run. Unfortunately, we came up one game short of where we wanted to be."
Lambert, a four-year varsity player and one of the state's top class of 2019 prospects, finished with 12 points, 4 rebounds and 2 assists in his final high school game. He made just 4 of 17 shots from the floor and was feeling the sting of the loss in the media room following the emotional contest.
"I kind of let my team down and I kind of let the city down," Lambert said. "I really can't believe what just happened."
Garceau, though, was quick to credit Lambert for the Jets' successful season.
"Chombi has been phenomenal for us the past four seasons," Garceau said. "He's a gym rat and he's a competitor. He has meant a great deal to our program."
The vision of sophomore point guard Preston Ruedinger gave Lourdes Academy one of the biggest basketball victories in the history of the school Thursday night.
With the WIAA Division 4 State Tournament semi-final game with Osseo-Fairchild tied at 68 and the final seconds of regulation time ticking off the clock, Ruedinger got the ball from teammate Henry Noone near the top of the key, took a couple of hard dribbles toward the lane and then delivered a spot-on bounce back to teammate Hayden Jones.
Jones caught the pass and went up for what proved to be the game-winning layup with :01.5 seconds left.
After a timeout, Osseo-Fairchild threw a length of the court pass to senior Logan Mulhern. Mulhern, who torched Lourdes Academy all night long en route to finishing with 33 points and 20 rebounds, caught the pass and put up a one-handed shot from the right baseline that bounced off the rim as the final horn sounded.
The emotional victory sends Lourdes Academy (26-1) into Saturday's Division 4 title game against New Glarus (25-2). Lourdes finished second in the 2005 Division 4 tournament, the only other time the Knights have advanced to a title game on the WIAA's biggest stage.
Osseo-Fairchild (24-3) had built an eight-point lead (58-50) with 7:15 remaining, but Lourdes battled back and got to even at 62 with 2:49 left on a free throw by Ruedinger.
Mulhern then scored five straight points to give the Thunder a 67-62 advantage with 1:43 remaining. Lourdes, though, was far from finished.
Ruedinger made a pull-up jumper in the lane and Noone drilled a huge three-point shot from the right baseline to deadlock the game at 68 with :57 left.
Mulhern missed a jump shot in the lane with :45 remaining, setting the stage for Jones' game-clinching layup.
"We battled back," Lourdes coach Brad Clark said. "One thing our guys have is that they don't quit."
Lourdes looked like it was going to run away and hide in the first half as the Knights were hitting three-point shots and running the court well while taking a 36-20 lead with 4:01 left before intermission.
But Osseo-Fairchild outscored 14-3 the rest of the way and got a triple from Mulhern with seven seconds left to go into the lockerroom down 39-34.
The Thunder picked up their strong play again early in the second half. Osseo-Fairchild took a 41-39 lead at the 16:38 mark and didn't trail again until Jones' final basket.
"The game kind of played out to our expectations," Osseo-Fairchild coach Tim Popple said. "We knew they could shoot the lights out. We switched defenses about 50 times in the second half to try to get them to miss some shots. They didn't shoot nearly as well in the second half and we knew that if we could stop them, that we could score."