Junior guard Theresa Lisch paced the Billikens with 21 points, 11 rebounds and seven assists. Senior forward Heather King scored a season-high 19 points, while junior center Amanda Kemezys added 12 points.
Daugherty, a sophomore, scored nine points in the final 1:03. She made a 3-pointer from the right wing with 20 seconds left to give the Flyers a 69-66 lead and hit two free throws with 10.3 seconds remaining to put Dayton ahead by five. She made a layup with 1 second left.
Daugherty finished with 19 points, as did junior Kendel Ross. That duo combined for 29 points in the second half. Freshman Kayla Moses was a sparkplug off the bench with 15 points on six-of-eight shooting in 20 minutes. Freshman Justine Raterman had 13 rebounds.
Saint Louis (6-10 overall, 0-1 in league play) had won its previous two games, against Ball State and Hampton. Dayton improved to 12-5 overall with its first Atlantic 10 victory.
The Billikens used a 12-0 run — with eight points from Lisch and four from Lauren Woods — late in the first half to take an eight-point lead and held a 34-26 at halftime.
Lisch had 15 points and King had 11 in the first half. The hot-shooting Billikens made 59.1 percent (13 of 22) of their field goal attempts, their highest shooting percentage for any half this season, including two of three 3-point attempts. They also made six of seven free throw attempts.
Saint Louis led by as many as 12 early in the second half and, after Dayton cut that deficit to just three points, led by 11 points with 10 minutes remaining.
But Dayton responded with an 11-0 run, including four points from freshman Kayla Moses, and the score with 6:20 left on a bucket from freshman Justine Raterman.
The teams exchanged buckets down the stretch.
SLU sophomore Lauren Woods tied the score at 66 with a drive and basket with 47 seconds remaining. But Daugherty's 3-pointer with 20 seconds left proved to be too much for the Billikens to overcome.
After being outscored by eight points in the first half, Dayton outscored SLU 47-34 in the second half. The Flyers made 62.5 percent of their shots (20 of 32) in the final 20 minutes.
Saint Louis is back in action at 7 p.m. on Monday against Fordham at Chaifetz Arena. The game will be broadcast by the CBS College Sports network.
NOTES: Junior guard Katie Paganelli missed her fourth straight game with a knee injury. The Billikens went 2-1 in their first three without her, losing only to Oklahoma. … SLU signee Ashley Hanlen, a senior guard at nearby St. Joseph's Academy, will miss the rest of her high school senior after slipping on some ice on the way to an early morning workout and breaking her ankle. The 5-foot-7 Hanlen was averaging 9.3 points and had hit 16 3-pointers.