The Trojanns jumped out to an 18-7 lead and never trailed. Spencer rallied to tie the score at 32-32 with 4:05 left in the fourth quarter, only to have the Trojanns finish the game with an 8-3 run.
Sophomore Whitney Jacobs led Atlantic with 13 points. The sophomore connected on four three-point goals and had three steals. Sarah Wernimont added 10 points for the Trojanns.
Anne Morgan led Spencer with 14 points and seven rebounds while Morgan Brandt added 12.
Atlantic won its 10th-straight first round game and advances to the Class 3A semifinals to face top-ranked Waukon. Spencer ends its season at 19-8.
Spencer (19-7) 7 7 11 10 -- 35
Atlantic (23-2) 18 7 5 10 -- 40