The victory was the first for the Warriors in the LHSAA playoffs in the the school’s history.
Northside, who remained unbeaten at home this year (13-0), improved to 22-7 and will now play host to Claiborne Christian Tuesday in a regional matchup.
Friday’s contest against McManus was never in doubt as the Warriors stormed out to a 19-0 advantage in the first frame before extending their lead to 43-13 at the break.
Northside’s reserves hit the court in the second half and outscored McManus 40-27 over the final 16 minutes.
The Warriors had 10 players score in the victory.
Ben Rogers and Pierce Rivera led the charge with 23 and 12 points respectively.
Joseph Trahan followed with 10 points and Grant Williams added nine. Kade Miller and Nick Gotte each scored seven points; B.J. Starks scored six; Kaleb Clement scored five and Nathan Zeller and Josh Wheeler each scored two.
Blair Brinson paced McManus with 15 points and Brandon Warren scored 10.