Upper St. Clair sophomore Brooks York made sure a historic comeback would become just a footnote in a crazy WPIAL Class 5A baseball semifinal Thursday.

York hit a two-run homer in the top of the eighth inning at Joe Maize Field at Peterswood Park in Peters Township on to lift No. 12 Upper St. Clair past No. 8 Montour, 13-10.

The Panthers young catcher’s heroic shot erased one of the greatest comebacks in WPIAL playoff history after the Spartans scored nine runs in the bottom of the seventh inning to turn a 10-1 deficit into an extra-inning thriller.

“Nothing like this. Nothing ever like this,” Upper St. Clair coach Jeff Donati said. “I’ve probably coached in 500, 600 games and I’ve never seen anything like this. I didn’t have a great feeling going into the last inning. Things snowballed and they got a couple of hits, but what makes you so proud is our kids could have folded. This group never flinched.”

Mixed emotions were all over the face of Montour coach Bob Janeda afterward as well.

“I’ve never seen anything like this. It was wild,” he said. “We knew if we could get to their bullpen, we had a shot. We knew what they had left. We put the take sign up and it worked. I have my No. 4 hitter up with the winning run 90 feet away in the bottom of the seventh.”

USC led 10-1 with all its runs coming in the final four innings of regulation, including three more insurance runs in the top of the seventh that nobody knew at the time they desperately needed.

Panthers starting pitcher Max Dietrick was excellent through six innings, allowing only one unearned run.

“Our game plan was to get their starter out early, and we didn’t do it,” Janeda said. “I tip my hat to him.”

However, he started the bottom of the seventh at 101 pitches and yielded back-to-back singles to Lane Martinec and Zachary Ciamacco.

Over the pitch limit of 105, Dietrick was replace by Ethan Capobres, who yielded a single to Zander Stern to load the bases, then walked Caleb Ambruster, Matteo Weber and Michael Ivanoff to force in the first three runs.

Tanner Schroeck entered and the mound struggles continued.

A sac fly by Dalton Young was followed by a base hit to reload the bases by Tyler Puffer and a run-scoring single by Sal Magliocco as the Montour batted around and still had the bases loaded with one out, now trailing, 10-6.

Martinec walked to force home a run, Ciamacco singled in another and Stern hit into a fielder’s choice at second to make the score 10-9 with runners on the corner and two out.

“It’s a crazy game,” Janada said. “We’re down 10-1, then all of a sudden, 20 minutes later, we have the tying run at third base.”

Armbruster hit a hot smash off the third baseman’s glove and into foul territory that plated the tying run as Stern advanced to third.

Weber walked to reload the bases before a ground ball up the middle was stopped by USC second basemen Finn Baird, who flipped to shortstop Nico D’Orazio for a force out that ended the historic inning.

“Huge play, great play by Finn and Nico,” Donati said. “If they don’t make that play, the runs scores from third and it’s over.”

If Upper St. Clair was stunned and shell-shocked, it didn’t show in the eighth inning.

Against Spartans reliever Gavin Foley, Cooper Stutzman was hit by a pitch and then York delivered a two-run bomb over the left-field fence and into the parking lot to put the Panthers back up, 12-10.

“There was no doubt in my mind that we we’re going to win this game,” York said about his mindset heading into extra innings. “I was told to bunt, but it didn’t work out, so I was just looking for a line drive somewhere.

“Off the barrel, if felt pretty good, but at first, I didn’t think it was out until I rounded first base.”

USC added another run off Stern when Luke Marchinsky hit into a fielder’s choice and stole second on a failed pickoff. Baird then walked and D’Orazio doubled home the 13th and final run of the game.

Michael Ivanoff started for Montour and limited high-scoring Upper St. Clair to only one run through four innings.

The Panthers finally got to him and chased him in the fifth inning when they scored five times to take a 6-1 lead.

A single by Nolan Wilson scored Baird to break the 1-1 tie, a bunt by Stutzman scored D’Orazio and a double by York scored two more. Schroeck singled home the fifth run of the inning.

The Panthers scored a run in the sixth inning and added on three more on a Marchinsky RBI single and a two-run base hit by D’Orazio, making it 10-1 and setting up the dramatic bottom of the seventh.

“They are a good ballclub,” Janeda said. “They swing the bats. The first three inning they didn’t score, but then they added runs every inning so kudos to them.”

Dietrick allowed two earned runs in 6-plus innings on eight hits with two walks and three strikeouts.

“He was so good, coming off pitching in our last game,” Donati said. “He didn’t flinch, fastball in, fastball out, curveball, held runners well, he fielded the position well. That kid’s been with me for three years and he’s a dog.”

Montour falls to 17-6 and will prepare to play Thomas Jefferson for a third time this season in the Class 5A consolation game next week. The Jaguars swept the Spartans in mid-April, 5-0 and 4-1.

Upper St. Clair is headed for the WPIAL 5A championship game with a record of 14-9.

The Panthers will also face a familiar foe in South Fayette, a team that beat them twice this season, 17-6 and 7-6.

“Hats off to (Montour), those kids didn’t quit and they came back,” Donati said. “In 32 years, I never thought we could hit our way off the island the way we are. We’re averaging 12 runs and 16 hits in the playoffs.

“We’re going to have to win one, 3-2, 2-1 at some point. That’s the reality of playoff baseball. Hopefully it works out next week.”