Donner bested Southern Miss's Kathrin Waidner 7-5, 6-2 at No. 4 singles while Aranda downed Mahitha Dadireddy 1-6, 6-3, 6-4.
"Kali continues to show her growth as a player being able to maintain her focus and compete at the highest levels," said SIUE Head Coach Jason Coomer.
"Lexi got off to a slow start" he added. "Once she was able to regain her composure on the court, her level of play continued to rise in the second and third set."
Aranda improved to 12-4 in singles.
"We need Lexi to continue to compete at the level she finished today, but we need her to do that earlier in matches," said Coomer.
Southern Miss improved to 3-8 overall by winning the doubles point and four singles matches in straight sets. SIUE's overall record fell to 4-5.
"We have to rebound quickly for our match tomorrow with Loyola," said Coomer. "Once we do that, we'll refocus for New Orleans on Sunday." Saturday's first serve is set for 11 a.m.