The St. Vincent sophomore was perfect from the field and helped the Indians cruise to a 52-34 girls basketball victory that wasn't nearly as close.
Mattingly went 6 of 6 from the field and converted 3 of 5 free throws for 15 points before the intermission.
"She works pretty hard and she just came out tonight ready to play," St. Vincent coach Terry Wengert said. "She did a lot of good things. She's coming into her own. She's a sophomore and she's really beginning to play well, so I was really proud of her tonight."
Mattingly's play inside helped St. Vincent (9-2) jump out to a 16-2 lead after one quarter and 36-8 advantage at the break.
Mattingly's play inside helped loosen the Lancers' defense, and senior guards Courtney Heberlie and Storm French took advantage. The pair combined to score 21 points.
"When she makes some shots inside, it draws the defense in to her trying to stop her," Heberlie said. "It opens up the outside for us outside shooters. It just works both ways. Hopefully we're both making them, outside and inside."
St. Vincent's defense suffocated the Lancers in the first half. The Indians enjoyed a 28-point lead at halftime because the Lancers shot 12 percent from the field (3 of 26) during the first two quarters.
"We did come out with great defense," Heberlie said. "We'd worked on it in practice. Not really technically for this game, but the last couple weeks we've been working on our defense. It worked tonight."
"We were just moving the ball well," Heberlie said. "We came out with a different offense, and we've been working on one of our new offenses. Just moving the ball quickly and getting some open looks."
The Lancers' offense improved minimally in the third quarter. St. Pius went 3 of 12 from the field in that period.
"We worked a lot on making sure we didn't cheat over on our defense and make sure we covered everyone," Mattingly said.
St. Pius made the score somewhat respectable by outscoring the Indians by 15 points in the final quarter. St. Vincent committed nine turnovers in the fourth quarter, but Wengert substituted freely in the second half, especially the final period.
"Getting a good lead gets some people off the bench, keeps us fresh for tomorrow night," Heberlie said.
The Indians and Panthers played last month, and Meadow Heights earned a 61-40 win. The championship game at Delta is scheduled to tip at 7:30 p.m. today.
ST. PIUS (34) -- Holly Magre 8, Caroline Basler 6, Alex Linderer 9, Haylee Eastridge 2, Jessica Bax 2, Christina Hovatter 3, Michayla Boyer 2, Madeline Smith 2. FG 14, FT 6-17, F 9. (3-pointers: Hovatter 1, Magre 1. Fouled out: none)
ST. VINCENT (52) -- Storm French 7, Courtney Heberlie 14, Katie Mattingly 15, Kayla Seabaugh 6, Dani Hogard 4, Stephanie Hoyt 2, Kelly Welker 2, Kelley Haertling 2. FG 23, FT 3-10, F 13. (3-pointers: French 1, Heberlie 2. Fouled out: Hoyt)