Shooting woes were Auburn's downfall as the Tigers hit just 23-60 field goals vs. the Phoenix, which made 21-49.
Green Bay was 9-20 on three pointers and made 13-19 free throws while the Tigers were 6-15 on threes and 4-4 at the free throw line.
The Tigers will play in the consolation game at 2 p.m. CST on Saturday vs. Louisville, which fell 59-56 to the host team, the University of Vermont.
Senior guard Natasha Brackett led the Tigers in scoring with 17 points and another senior guard, Taneisha Thompson, added 15 for the Tigers. Brackett made 7-17 field goals, including three of five treys, and Thompson hit 5-10 shots.
Junior forward Louise Emeagi led the Tigers on the boards with a career-best 16 rebounds and chipped with eight more points and five assists. Center Marita Payne added eight points and seven rebounds for the Tigers.
The Tigers overcame a 20-10 first half deficit to lead 35-32 at intermission. The teams exchanged leads in the first 11 minutes of the second half. Auburn's last lead was 52-51 on a basket by Thompson, but turnovers and cold shooting down the stretch were the downfall for the Tigers.
After hitting 46.9 percent of their field goals in the first half, the Tigers slumped to 28.6 percent shooting in the final 20 minutes. The Tigers also committed a dozen turnovers in the second half after having just five at intermission.
"Our execution right now has a ways to go to get the level we are wanting," Fortner said. "I think we had a little more panic in the second half than we were wanting to have. When you get down, you start looking at the clock and the score and start to panic a little bit. Once that happened, the turnovers started setting in."
Five Green Bay players scored in double figures. Abby Sharlow and Tiffany Mor led the Phoenix with 12 points apiece.
Following Saturday's game at Patrick Gymnasium vs. Louisville, Auburn's home opener is on Monday at 11:30 a.m. vs. Chattanooga.