In what was expected to be a tightly contested 26th Howard County Wrestling Tournament, dual-meet champion Oakland Mills emerged from the quarterfinal round with a slim lead over two-time defending tournament champion Hammond, 61.5 to 58.
Both teams advanced nine wrestlers to the semifinal round of the championship bracket.
Atholton, in third place with 52 points, remained in contention by advancing eight wrestlers. Fourth-place Centennial with 47 points, advanced seven wrestlers.
Glenelg and Wilde Lake, each with 36 points, advanced six wrestlers apiece. Howard (35 points) advanced five wrestlers and Mount Hebron (12 points) advanced two.
Howard suffered a significant setback when 112-pounder T.J. Dameron, who was 16-4 and fourth-seeded, failed to make weight by 1 pound and was disqualified.
At 140 pounds, Atholton's Brendan Trexler scored an upset over Glenelg's Tate Fenner with a pin at 5:26. Fenner was 12-6 and Trexler was 12-11.
The varsity semifinals begin at 1 p.m. today, with the championship finals set to start at 7 p.m.