HALLSVILLE, Texas—Having left a hospital bed only a couple of days prior to Saturday’s Class 2A regional quarterfinal matchup with seventh-ranked New Diana, Derrick Ray seemed the least likely to emerge as the series hero.

Yet the New Boston junior played the role to the hilt Saturday at Hallsville High School, rapping a bases-loaded triple and driving in an insurance run with a squeeze bunt to help the Lions to a 6-4 victory in the rubber game of the three-game set.

For good measure, Ray threw six innings of relief in the opener of Saturday’s doubleheader, won by the E...