FOX CHAPEL — Cinderella's slipper is fitting Mars well.

The 11th-seeded Planets advanced to the WPIAL Class AAA softball championship game for the first time since 2006 Thursday, building an early 7-0 lead and holding on for a 7-6 win over Elizabeth Forward at Fox Chapel High School.

Mars has rung up three consecutive one-win victories in the tournament, all against higher-seeded teams. The Planets (12-4) will face Thomas Jefferson (14-6) — which upset Greensburg Salem, 4-3, in the other semifinal — for the WPIAL title Thursday at California (Pa.) University.

“Cinderella? Yeah, we are,” Planets coach Michele Goodworth said. “We're enjoying that role.

“Everyone is just doing her part right now. We're just playing ball. Honestly, I haven't even looked at the seeds.”

Perhaps the Warriors should have looked at Erin Hershman's throwing arm.

Elizabeth Forward put together six singles during a four-run sixth inning to pull within 7-6, but the rally could have proven disastrous to Mars if not for its senior center fielder.

Ashley Baker singled to left to begin the frame and scored on Kelsey Benedek's infield single. Benedek moved to second on an errant throw.

Lauren Cain singled to center. Hershman quickly got to the ball and fired to the plate. Her throw was up the third-base line a bit, but freshman catcher Marina Manuppelli snagged the ball, reached across the baseline and tagged Benedek out.

“I definitely appreciated that play,” Mars pitcher Niki Schelegel said. “I always rely on my defense. We'll take outs any way we can get them.”

Hershman said the outfield assist was her first of the season.

“When balls come out to center field, there's always a chance someone will try to score,” she said. “I haven't had many chances to throw anybody out this year, though.

“When I saw her going around third, I knew I had a chance to get her.”

E-F coach Harry Rutherford tried stopping the runner at third.

“You never want to make the first out at third or home,” Rutherford said. “She ran right through a stop sign. I was yelling 'back, back, back' and she kept on going.”

Singles by Courtney Hrabosky and Jen Keefer followed as the Warrior rally continued. With two outs and the tying run on second, Schlegel struck out Jessica Cartia to end the inning.

Schlegel retired the Warriors in order in the seventh — the only inning E-F did not produce a hit — to secure the win.

“Erin is the best athlete on our team and she came up big for us,” Goodworth said. “That play was probably the difference in the game.

“Niki always keeps her composure on the mound. She's done a lot of pitching, travel and summer ball, and she's confident out there. I never thought of taking her out. This was her game all the way.”

Mars scored five runs after the first two batters were retired in the second inning. No.'s 8 and 9 hitters Shelby Huber and Jeanna Sybert both singled and an infield hit by Suzanne Papik loaded the bases.

Blake Kitt and Kasey Jones delivered two-run singles in the inning and a run-scoring single by Manuppelli capped the rally.

Papik and Kitt greeted E-F starting pitcher Lauren Mathews with singles to begin the fourth. That prompted Rutherford to insert Sarah Turek on the mound.

“I found out that Lauren had hurt her back a couple of days ago and didn't tell anybody,” Rutherford said. “She was hurting, so I got her out of there.”

Turek is the Warriors' regular starter, but returned only two weeks ago from an injury herself. Mars managed only two singles against Turek the rest of the game.

But Hershman and Jones produced RBI groundouts in the fourth to build the Mars lead to 7-0.

“There was a lot of game left,” Goodworth said. “We coaches started counting the outs backward, trying to get there.”

E-F scored singe runs in the fourth and fifth innings before its four-run outburst in the sixth. Every player in the Warriors' lineup had at least one hit.

But they weren't enough.

Papik and Kitt had two singles each for Mars, both scoring twice. Jones had three RBI.

“This is awesome,” Hershman said of going to the WPIAL title game. “I never thought we would go this far. Not at all.”

Mars 050 200 0 — 7 10 2

Eliz. Forward 000 114 0 — 6 12 2

W: Niki Schelegel 7IP (3K, 1BB). L: Lauren Mathews 3IP (1K, 2BB).

Mars (12-4): Suzanne Papik 2-1B 2-R, Blake Kitt 2-1B 2-R 2-RBI, Erin Hershman 1B RBI, Kasey Jones 1B 3-RBI, Marina Manuppelli 1B RBI, Mallory Eperesi 1B, Shelby Huber 1B, Jeanna Sybert 1B

Elizabeth Forward (14-7): Courtney Hrabosky 1B, Jen Keefer 2-1B RBI, Caitlin Aruico 1B 2B RBI, McKenna Kern 1B RBI, Jessica Cartia 2B RBI, Lexi Ribarchak 1B, Ashley Baker 2B 1B, Kelsey Benedk 1B RBI, Lauren Cain 1B

Thursday: WPIAL Class AAA Championship-Mars vs. Thomas Jefferson, California (Pa.) University, time TBA