AUGUSTA – Riley Robinson scored 12 of his 23 points in the fourth quarter to lead Dirigo to a 50-47 victory over Old Orchard Beach in a Western Class C boys’ basketball quarterfinal Monday at the Augusta Civic Center.

No. 3 Dirigo (18-1) will face Waynflete in a regional semifinal at 7 p.m. Thursday at the Civic Center.

OOB finishes at 14-5.