Nick Emery added 16 points, while Eric Mika scored 13 as the Knights (10-0) won its third game in three days in the tournament, which pits some of the best teams in the entire country against one another.
The Knights trailed by one point at the half, but took control of the game outscoring Southwind 24-12 in the third quarter.
Lone Peak, the first Utah team to ever be ranked #1 in the country, has already defeated #3 Chester (Pa.) and Callaway (Miss.).
Lone Peak will face #10 Montverde Academy (Fla.) in the championship game Saturday night.