ABERDEEN — Lower Brule rode the hot hand of Gavin Thigh into the Class B semifinals.

Thigh, who is one of the Sioux’s dynamic scoring guards, poured in 34 points as Lower Brule downed Castlewood by a 67-55 score at Wachs Arena on Thursday. Lower Brule will play White River at 6 p.m. Friday in the Class B semifinals. 

Thigh was instrumental in lifting Lower Brule (21-3) and finished 10 of 13 from the field, including 6 of 8 from the 3-point line. 

“I had confidence and I was squaring up to the rim and just shot my shot,” said Thigh, who was 8 of 10 from the free-throw line. 

Thigh tossed in three 3-pointers in the first quarter, sparking a 17-4 start and a 21-12 lead after the first eight minutes. He was 6 of 6 from the field and 3 of 3 from the 3-point line at halftime. 

“That was probably the best start I’ve ever had in my senior (year),” Thigh said. 

Brian LaRoche Jr., added 15 points to complement Thigh’s scoring output. 

The Warriors (18-6) were led by 6-foot-8 Bryon Laue with 25 points and 14 rebounds. Quincy Thu added 11 points and six boards. 

Castlewood's Bryon Laue (33) puts down a dunk through the Lower Brule defense during a game on the first day of the Class B State tournament on Thursday at the Barnett Center. (Matt Gade / For 605 Sports)

Castlewood used a 19-18 second quarter to cut the halftime deficit to 39-31. Lower Brule seized back control with a Thigh and LaRoche Jr., 7-0 run to start the second half. 

“We were trying to control the game,” Thigh said. “We weren’t trying to let them get a hold of us. We were just trying to attack them and get to the rim.” 

The Sioux kept the Warriors from striking distance the rest of the way. It was Lower Brule and Castlewood’s second meeting this season, with Lower Brule winning on a LaRoche Jr., 3-pointer at the buzzer the first time. 

Thigh said Lower Brule honed in on their defense in the second matchup. 

“I just think we didn’t really communicate on defense like we did in this game,” Thigh said. “Even though we were in foul trouble we still tried to play smart.”

The Sioux will now play another familiar foe in White River. Lower Brule outlasted White River in a triple-overtime thriller in last season’s semifinals, en route to a runner-up finish.  

Castlewood will play Faith at noon in the consolation semifinals.