Sheldon held an 11-9 lead after the first quarter, but Storm Lake led 21-16 at the half. It was 34-30 Tornadoes after three quarters.
"The last minute we made a deadly turnover and they scored a layup right under the basket," Storm Lake coach Stacey VanDerSloot said. "The girls played great. They fought hard and deserved to win. Sheldon just stepped up in the fourth quarter and shot the lights out."
Billie Blanchard scored 10 points to lead Storm Lake. Chelsea Anderson, Brooke Overturf and Jenny Woodford all had six points apiece.
Storm Lake made 9 of 11 free throws compared to 13 of 27 for Sheldon.
Storm Lake is now 3-5 in the league and 5-6 overall.
Meredith Vos led Sheldon with 15 points.
Storm Lake St. Mary's 53
Sara Larsen poured in 23 points to lead all scorers as Newell-Fonda upended Storm Lake St. Mary's in Northwest Conference action Friday night at Newell.
Newell-Fonda held a 19-6 lead after one quarter of play before clinging to a 40-29 halftime lead. It was 63-33 after three periods.
Ashley Loos scored 13 points for the Mustangs. Jenny Scharn added nine, as did Jen Schumann and Erin Kies.
Larsen collected 10 rebounds, while Ashley Bellinghausen added four. Loos handed out two assists, as did Scharn. Larsen charted six steals.
Michelle Drey scored 11 points to lead St. Mary's. Peggy Ploeger added 10 points and Michelle Weaver eight.
Megan Kestel cleared 10 rebounds and Drey and Jen Petersen both had five. Bri Barber and Marisha Imming each had three steals, while Kassie Drey and Ploeger charted two steals apiece for the Panthers, now 5-4 overall.
St. Mary's made 19 of 69 field goals for 28 percent. The Mustangs were 25 of 64 for 39 percent.
"After we cut it to 26-22, we had just a little bit of a letdown for a few minutes that made a big difference in the game," St. Mary's coach Ryan Berg said. "Had we been able to keep it that close going into halftime and made a few more of our close-in shots, we could have been more competitive."
Sioux Central 47
Jill Smith scored 23 points and handed out 10 assists to help send Aurelia past Sioux Central in a Northwest Conference game on Friday night at Aurelia.
Aurelia led 11-7 after the first quarter before extending to a 31-23 halftime lead. It was 41-37 after three periods. The Bulldogs used a 13-3 spurt to take a 54-40 lead with 4 minutes remaining.
Kim Parker contributed 15 points, 11 rebounds and three assists. Nicole Benes added 13 points and three blocked shots.
Smith and Vernice Alfred each had five rebounds. Jennifer Cougill added four steals and three assists for Aurelia, now 5-5 overall.
Kelli Terrell scored 17 points to lead Sioux Central. Amanda Enderton added 13.
"This was a good win for us coming out of break," Aurelia coach Scott Bailey said. "We still need to put a full game together, but I thought we made stops when we needed to and put the ball in the basket."
Jenna Malcom poured in 24 points and Tessa Schmidt added 19 to help send Schaller-Crestland past Pomeroy-Palmer in Northwest Conference play on Friday night at Pomeroy.
Schaller-Crestland led 13-12 after the first quarter of play and took a 28-25 halftime lead. The Wildcats extended their lead to 49-30 by the end of the third quarter.
"We forced them into a lot of turnovers and kind of got the game into an up-tempo style by pressing," Schaller-Crestland coach Mike Green said. "Our height took its toll on them inside."
Monica Bloyer scored 13 points for Schaller-Crestland, now 4-3 in the league and 4-6 overall.
Schaller-Crestland made 27 field goals to Pomeroy-Palmer's 13.