At Dallas, Michael Bufalino scored 12 of his 20 points in the second quarter when the second-seeded Mountaineers outscored No. 7 Wallenpaupack, 22-6.
Cameron Faux scored eight points for Dallas, while Jude Nocito finished with seven. Dallas will host No. 6 seed West Scranton on Friday night at 7.
Justin Blanding scored 14 points for the Buckhorns.