PORTLAND, Maine — The No. 3 Thornton Academy boys basketball team was giving the No. 2 South Portland Red Riots all they could handle in the first half of Tuesday night’s Class AA South semifinal game, but the Golden Trojans were unable to keep it going in the second half. The Red Riots outscored TA 17-4 in the third quarter as they punched their ticket to a third straight regional final with a 51-36 victory at the Cross Insurance Arena in Portland. South Portland led the Trojans by a 13-12 score after the opening quarter and would push the lead to 25-20 at the halftime break. The Riots took control with the 13-point advantage in the third before TA outscored South Portland 12-9 in the final quarter. Will Chapman led TA with eight points and Will Mitchell added six points.