Goll, Stevenson soak up a victory at Glenbrook N.

So filthy good was Mitchell Goll’s shot that he might never better it.

During a second-inning at-bat in Friday’s Class 4A Glenbrook North sectional semifinal, the Stevenson junior fouled a pitch by Glenbrook South’s Kyle Pauly over the backstop. The baseball splashed into a garbage can filled with soggy contents due to Thursday’s downpour.

“Did it really?” said Goll, who was unaware of his funny foul ball.

Nothing but wet.

Goll hit another shot in the fourth.

It was fair. And far.

His first varsity home run erased a 2-0 deficit, and he and his teammates continued to execute en route to a 6-4 upset of second-seeded Glenbrook South in Northbrook. No. 6 Stevenson (21-11) will face No. 5 Libertyville (25-11) at 11 a.m. Saturday in a showdown of North Suburban Conference Lake Division rivals. The Patriots and Wildcats split their two games during NSC Lake play.

“We don’t like each other,” Goll, a lefty who’s expected to start on the mound, said with a grin.

“We know Libertyville’s tough,” said Stevenson coach Paul Mazzuca, who as a sophomore call-up for Rolling Meadows in the 1980s was a baseball teammate briefly of Libertyville coach Jim Schurr, who’s two grades older. “It’s going to be a great NSC battle. I’m really proud for the conference.”

Goll, a second-year varsity player who only pitched last season, worked his bat magic throughout the game. His sacrifice fly in the fifth was part of a pivotal 4-run inning, and his seventh-inning single gave him a 2-for-3 day.

“He’s a heck of an athlete,” winning pitcher Matt Allen said. “He keeps our team up. He’s a junior that’s going to be very good next year.”

Allen will be pitching for the University of Iowa next year. The right-hander threw 4²⁄₃ innings, allowing all 4 GBS runs (2 earned), while striking out a pair. An error loaded the bases for Glenbrook South (26-7) with none out in the bottom of the fifth, before Allen induced a pair of groundballs to keep the inning from getting out of hand.

Stevenson led 6-2 after its half of the fifth. Max Cohen’s RBI single ended Allen’s day on the mound.

“That’s Matt Allen to a T — compete, battle my butt off,” Mazzuca said of his ace’s effort. “He didn’t want to come out of the game, but he was right here in the front (by the dugout fence) cheering on his teammates. He’s a great teammate.”

“You got to have guts out there,” said Allen, who improved to 5-4. “I just fight and do what I do. I love the game.”

With Glenbrook South runners on first and second in the fifth, Jordan Sheinkop got the final out on a groundball to first baseman Goll, who dived to knock down the ball before retrieving it and stepping on the bag.

Sheinkop then threw the sixth and seventh innings, as well, allowing a single and striking out two to earn the save. The George Washington-bound Sheinkop was a starter during the regular season.

“Going into the regionals, we knew we were going to go Allen (to pitch the opener) and then, if we won, it was going to be Goll, just because we knew Carmel had all those lefties,” Mazzuca said. “I told Jordan, ‘You’re going to be in relief.’ Being a starter, we knew he had the stamina to go long relief, and obviously we were real confident with him coming in.”

Tommy O’Hara’s double was Glenbrook South’s big hit in its 2-run second off Allen, but Stevenson responded in the fourth off lefy starter Pauly. Zach Novoselsky (3-for-4) singled, and then Goll belted a pitch over the fence in left-center field.

“I just a got a good pitch up in the zone and I kind of tomahawked it out,” Goll said.

Michael Banakis and Willie Bourbon (1-for-3) drew back-to-back walks to start the Stevenson fifth. After Greg Voss’ sacrifice bunt was bobbled to load the bases, Jimmy Marchese’s single gave the Patriots a 3-2 lead. Goll’s one-out sacrifice fly made it 4-2, before Austin Black delivered a clutch 2-run single off Pauly.

Pauly had been dealing with a blister on his throwing hand for most of May.

“He’s pitched only 4 innings in three weeks,” Glenbrook South coach Dave Lindley said. “It’s hard to take out your No. 1 pitcher. I knew he was about done, but there were two left-handers (Black and Tony Heiser) coming up.”

So Stevenson, which won only four of its first 10 games, now finds itself in position to advance to Monday’s Rockford supersectional at RiverHawks Stadium.

“Defense was a big problem (early in the season) and we were just really inconsistent,” Goll said. “Then again, we were a young team. I think we’ve been maturing throughout the year, and it’s showing right here.”