CANONSBURG — Gateway made a run. Mars made history.

The Planets shook off the Gators' third-quarter flurry — which trimmed an 11-point deficit to one — and recovered for a stunning 50-38 upset victory of the WPIAL champions in a PIAA Class 5A girls basketball quarterfinal Saturday at Canon-McMillan High School.

Gateway's loss snapped its 17-game winning streak.

The victory puts Mars (22-6) in the state semifinals for the first time since 1976. The Planets will face Archbishop Carroll (21-7) — a 51-32 winner over Oakland Catholic on Saturday — in the semifinals at 5:30 p.m. Tuesday at Bald Eagle Area High School.

“I'm so happy for these girls. They've worked so hard for this,” Mars coach Dana Petruska said.

Sophomore Bella Pelaia put Mars ahead for good with a trey at the 3:26 mark of the first quarter, giving the Planets a 7-4 lead. When Alek Johnson canned a trey less than two minutes into the third period, Mars' lead ballooned to 29-18.

“We knew they were gonna make a run,” Mars senior Lauren Wasylson said. “Coach told us to be prepared for it. They're too good not to put something together like they did.

“We didn't let it rattle us. I've been telling everyone on our team ... 'This is our season. This is our time.' We weren't going to let this slip away.”

A 12-2 Gateway run, capped by an offensive rebound and stick-back by 6-foot-3 Gator sophomore Lexi Jackson, pulled the Gators (25-4) within 31-30 with 3:12 left in the third quarter.

Wasylson hit a short baseline jumper and Pelaia converted a steal into a lay-up the other way to put the Planets back up by five.

A Pelaia trey early in the fourth period jumped the lead to six. Lay-ups by Tai Johnson and Wasylson gave Mars a 42-32 lead with 6:07 left.

“We knew we couldn't let up,” Tai Johnson said. “They were going to come with lots of energy and we had to match that energy.”

Back came Gateway, this time using a 6-0 run to trim the gap to 42-38 with 2:40 to play. But the Gators wouldn't score again.

Mars' final eight points came from the free throw line. The Planets converted 20 of 25 free throws on the day.

“We got some stops, but didn't convert enough offensively on our possessions down the stretch,” Gateway coach Curtis Williams said. “We didn't do enough to win the game.

“Mars made clutch shots, good plays when they had to. They played better than we did today.”

The Planets ran clock from the 2:40 mark down as Gateway only had two team fouls at the time.

“That was all them,” Petruska said of her girls on the floor. “I never told them they couldn't shoot. They knew the situation and they played to it. We have a mentally tough group.

“I told them they could drive to the basket, but we weren't going to get any lay-ups with their big girl in there. Either get fouled or dribble back out, and that's what they did.”

Johnson led the Planets with 22 points, converting 12 of 13 free throws. She had eight rebounds as well. Wasylson had 14 points and eight boards, Pelaia eight points and four boards, Alek Johnson five assists.

Jackson had 16 points and 20 rebounds for Gateway. Point guard Jordan Edwards had 10 points, five rebounds and three assists before fouling out with 1:10 to play.

Jackson sank just six of 21 shots from the floor. The Gators shot 25 percent (14 of 55) as a team.

“Rough shooting day ... It cost us,” Williams said.

“Bella did a fantastic job defending their big girl. She contested everything she did,” Wasylson said. “I can't put into words what this win means to me, means to all of us. I can't find the words.

“We shoot 10 free throws every day in practice. Coach puts pressure on us during that drill. Making free throws is critical in any game.”

Despite Jackson's domination on the boards, Mars matched Gateway in rebounds with 34.

“Rebounding was something we had to do. Everyone had to box out ... We got our share,” Johnson said.

Petruska thought back to Mars' 48-44 loss to Oakland Catholic in the WPIAL semifinals.

“The girls knew we let that one get away,” the coach said. “Rebounding is attitude, desire, wanting the ball. We had that today. These girls didn't want a repeat of that day.

“Sometimes good things can come from a loss.”

MARS 50

Alek Johnson 1-4 1-2 4, Lauren Wasylson 4-11 5-8 14, Nichole Summers 0-1 2-2 2, Tai Johnson 5-13 12-13 22, Bella Pelaia 3-6 0-0 8, Regan Kramm 0-0 0-0 0. Totals: 13-35 20-25 50.

GATEWAY 38

Joelle Jenkins 0-0 0-0 0, Jordan Edwards 3-12 4-4 10, Jenna Guido 1-7 0-0 3, Lexi Jackson 6-21 4-5 16, Annie Garness 1-2 0-0 2, Mary Kromka 3-12 0-0 7, Maya Paquet 0-1 0-2 0. Totals: 14-55 8-12 38.

Mars 14 10 11 15 — 50

Gateway8 10 14 6 — 38

3-point goals: A.Johnsaon,. Wasylson, Pelaia 2; Guido, Kromka

Tuesday: Mars vs. Archbishop Carroll, 5:30 p.m., at Bald Eagle Area High School, Wingate