The Pirates earned a spot in the upcoming Class 4A regional tournament with the victory in Game 3 of the best-of-three district series.
Groom's hit came in the top of the first inning after teammates Adam Roll and Devin Oldaker had reached base. His single drove in both runners and handed Poteau a 2-0 edge.
The Pirates went up 3-0 in the top of the fifth when Oldaker's bunt scored Jacob Davis from third.
Roland had three more base hits than Poteau, but managed only one run. It came in the bottom of the fifth when Zach Williams singled to score Ricky Acosta.
Roland pitcher Colton Daniel went the full seven innings on Friday, limiting the Pirates to four hits in all.
Roll picked up the win for Poteau, allowing seven hits while going the distance.
The two teams entered Friday with their district series tied 1-1. Poteau beat Roland 5-2 in Thursday's opening game before the Rangers evened the series with a 4-2 victory in the nightcap.
Zack Manchester's solo home run knotted the score at 2-2 in Game 2 and Acosta drove in the winning run before another run scored on an error.
