Augustana improves to 9-1 (2-1 NSIC), while U-Mary is now 4-3 (1-2 NSIC).
Augustana's Tessa Wilka blocked U-Mary's 3-point attempt by Kayla Schmidt that would have put U-Mary up by one point with 21 seconds remaining, and the Vikings got free throws from Kristi Board and Hayes in the game's final 18 seconds to seal the win.
Hayes was one of three Vikings to reach double figures as Megan Doyle and Alex Feeney scored 15 and 12 points, respectively.
Tessa Wilka snagged a game-high nine rebounds for the Vikings.
Doyle opened scoring for the Vikings in the first half, draining a 3-pointer and a pair of free throws for a quick 5-0 lead. With Augustana in the lead at 5-4, the Marauders made a jumper that gave them a one-point advantage. U-Mary didn't have another lead until 56 seconds left in the half.
Augustana's largest lead came at 6:55 when Emily Schulte hit a 3-pointer to put the Vikings up 26-18. U-Mary used the remainder of the half to erase the deficit, eventually taking a two-point lead over Augustana with 37 seconds left of play. Wilka made two shots from the line to close the half with a knot in the score at 35-35.
The Vikings were 31.3 percent from the field in the half, while U-Mary was 33.3 percent.
Augustana was 4 of 4 in the opening minutes of the second half to lead 43-39. The Vikings continued to lead despite a lingering Marauder club. The final tie came at 9:30 when Feeney sank a 3-pointer shortly after to give the Vikings back the lead.
Augustana continued with a scoring streak to hold a seven-point advantage with five minutes left in the game. U-Mary would make a comeback, however, as the Vikings went almost two minutes without converting a field goal.
Augustana's only deficit in the half came with 47 seconds remaining when U-Mary led 72-71.
Another Feeney 3-pointer with 32 seconds left gave the Vikings a 74-72 lead.
Wilka came up with her game-saving block on the ensuing possession, and free throws from Board and Hayes down the stretch closed the game.
The Vikings took advantage of their trips to the foul line, finishing the contest making 20 of their final 26 free throws, including late ones, to seal the victory. U-Mary went 13 of 17.
The Marauders outrebounded the Vikings 46-42, though Augustana managed 16 second-chance points.
Augustana connected on 12 3-pointers in the win.
The Vikings continue home action against Northern State Saturday at 4 p.m.