Senior forward David Dunham scored 19 points and had the go-ahead basket in the final minute of overtime as host Nashua South advanced to the Division I boys' basketball semifinals with a 61-57 win against upset-minded Dover on Friday night.

Dunham stayed hot in the postseason, hitting four 3-pointers. The No. 4 Purple Panthers (16-4) face Trinity of Manchester or Bedford on Tuesday at 7:30 p.m. at Lundholm Gym in Durham. Trinity hosts Bedford today at 4 p.m.

Tim Preston canned two free throws with 1.9 seconds remaining to ice the victory. Preston had 19 points, and Jack Preston chipped in 13. Dover's Billy Carroll netted 17 points, and Josh Cate had 15 points with four 3-pointers to pace the 12th-ranked Green Wave (9-11).

Spaulding 50, Exeter 45: At Rochester, 11th-seeded Exeter staged a dramatic fourth-quarter rally after trailing by as many as 15 points in the third quarter, but the Blue Hawks were plagued by missed free throws that stymied the upset bid. The visitors, who outscored the third-seeded Red Raiders by a margin of 17-9 in the fourth quarter, converted just 5-of-21 foul shots in the game.

After gaining a 31-22 halftime lead, Spaulding added to its advantage with a 10-6 third quarter. Dominic Paradis keyed the winners with 16 points in the game, and Alex Gray added 11. However, Exeter's Zack Holler and Tyler Russ, who finished with 15 and 13 points respectively, netted five points each in the fourth, while Spaulding could muster just two baskets.

Spaulding shot less than 50 percent from the free throw line as well, making 10-of-21 attempts. The Red Raiders missed nine free throws in the fourth and were guilty of seven turnovers. Spaulding meets No. 7 Bishop Guertin of Nashua in semifinal action as the D-I tournament continues.