Top-seed Winthrop defeated No. 9 Dirigo on Monday night, ousting the team with a 67-51 victory in the C South quarterfinals at the Augusta Civic Center. Winthrop’s record improves to 18-1 for the season, while Dirigo’s ends with a record of 8-12. Winthrop will play Traip Academy, who won in an upset against Boothbay Monday evening, in a semifinal match on Thursday, Feb.