WVU was out-scored by 28 points in the second half after taking a 14-point lead into the locker room at halftime.
"We just quit playing, I got to be honest with you," said WVU head coach Mike Carey. "It's a shame ... We shouldn't have lost that game."
Carey doesn't yet believe his team has secured an NCAA tournament bid yet despite beating three straight top 25 teams including No. 2 Notre Dame prior to Saturday's contest.
"We looked tired in the second half," Carey said. "We weren't posting hard. We were just standing there. We would shoot or miss or turn it over, and they would get a layup. I haven't seen us do that in a long, long time."
After holding DePaul to just 31 percent shooting in the first half – and just 1-of-10 from 3-point range – it seemed as if the Blue Demons couldn't miss in the second half.
DePaul shot 68 percent in the second half behind the hot shooting of freshman guard Brittany Hrynko who had 21 points. Three other players scored in double figures.
"My team has impressed me all season long in their ability to overcome some pretty stiff adversity," said DePaul head coach Doug Bruno. "They showed their grit in the second half."
In the first half, the pair combined for 19 points. Bussie and Dunning combined to finished with 23 points.
"They came out the first four minutes and played more aggressively than we did," Dunning said. "We all thought that we would come back, but it just never happened."
The Blue Demons started the second half down by 14 but went on a 14-0 run in the first six minutes to tie the game at 40. That lead would eventually grow to 20-3, as DePaul would take a 45-43 lead.
WVU really found no way to combat DePaul's offense in the second half. The Blue Demons took a 55-48 lead with less than eight minutes to play.
A three made it 60-50 and it only got worse from there. After a missed free throw, another three made it 65-51 to the groans of the sixth-largest crowd in program history at the WVU Coliseum.
"It was a great crowd, and it was for a great cause," Carey said. "We just showed no heart in the second half."
The second half by DePaul put to shame a solid first half by WVU. A 9-0 run in the first half would give the Mountaineers a 32-21 lead with 4:33 to play. Bussie and sophomore guard Christal Caldwell had 10 points apiece at the half. She finished with 16 points. Dunning had 10 rebounds at the half.
DePaul had 24 points off turnovers and 10 second-chance points.