The Crusaders (14-14, 7-10) were led by 10 kills apiece from Carly Dranginis and Becky Flores, plus nine each from Elayna Rice and Michelle Terpstra, as they avenged a 5-set loss in Anchorage on Sept. 15.
UAA trailed throughout the first set before catching fire late and erasing a 20-18 deficit with the last seven points, including a thundering kill by Mackey on set point.
But it was the Crusaders who came up with the key points in the next three frames and used a 4-0 run to end it after trailing 23-21 in the fourth.
The Seawolves conclude their 2012 campaign Saturday when they travel to regionally ranked Central Washington. First serve in Ellensburg is set for 7 p.m.