Tyler Weyenberg singled in Robert Stewart with the winning run in the bottom of the ninth inning Wednesday to send Hillgrove to a 7-6 victory and into its first baseball semifinal.

Hillgrove (26-7), an five-year-old school perhaps best known in sports for its upset of Camden County in the football playoffs last year, trailed 5-0 after three innings, tied the game 5-5 with a five-run fifth and then evened the score 6-6 in the bottom of the seventh on a home run by Tucker Ehmig to force extra innings.

“I was praying it would go by the shortstop,’’ said Wineburg, a sophomore. “When I saw he missed, I threw my hands in the air and everybody started running. Big dog pile.’’

Mill Creek (25-8) saved itself in the bottom of the seventh when pitcher Shane Seckinger entered with the bases loaded and one out and got Tyler Mauzy to line into a double play.

Seckinger continued to pitch well, allowing no hits to his first six batters, but Stewart, who entered the game as a pinch runner in the seventh, hit a one-out double to center. After an intentional walk, Wineburg stroked his second hit of the game past the shortstop for the game-winner.

As in Game 1 of this best-of-three Class AAAAA series, when Hillgrove trailed 3-0 after one inning but rallied to win, things looked bleak early.

A home run by Nick Tillman and a two-run single by Chandler Boyd gave Mill Creek a 3-0 lead after two innings, and back-to-back doubles by Aryan Rodriguez and Tillman led to a 5-0 lead after three and chased Hillgrove starter Max Oberkofler.

But Oberkofler came back to hit a two-run homer off Mill Creek starter Cody Pugh in the five-run fifth.

In the top of the seventh, Mill Creek took the lead on a single by Connor Kasten (2-for-3). Hillgrove didn’t field the hit cleanly in the outfield, allowing no play at the plate.

Ehmig’s homer tied the score, and Hillgrove loaded the bases before Mill Creek made a final stand.

The winning pitcher was Josh Hagerman, who pitched seven innings in relief, allowing five hits and no earned runs. Hagerman struck out six. He had pitched only 22 innings entering the game with no decisions.

“I knew yesterday that I’d be coming in [to relieve], but I didn’t know when,’’ Hagerman said. “I just went in there and tried to get it done. I was just in a zone.’’