XU pulled within five on a short jumper by Brown with 4:58 to play, but Dayton scored seven straight. It was 82-70 with 3:26 remaining.
During the final minutes, the Flyers did everything right, hitting nine straight free throws during one stretch.
They came up with big offensive rebounds in the second half, and matched Xavier shot for shot when it was close.
''They just wanted it more than us,'' XU's Darnell Williams said. ''If you let a team get open shots, they're going to nail them. That's why we lost.''
After Xavier tied it with the first basket of the second half, Dayton scored nine unanswered points and led 51-42 with 16:39 left.
Brown scored 12 of XU's next 19 points and put the Musketeers ahead 61-59 on a layup with 11:26 remaining.
It was tied at 61 and 63 before UD pulled away.
The teams play again Feb. 12 at Cincinnati Gardens.
''I guarantee it will be a different outcome,'' Brown said.
The end of the first half was eerily similar to last year's Xavier collapse, when Dayton came back from a 12-point deficit and won with a 19-1 run.
The Musketeers were ahead 30-19 Tuesday night with 8:16 to go before the half, and Dayton's leading scorer Perryman was on the bench with three fouls.
Then the Flyers went on a 20-6 run and took their first lead since 3-0 when Horton knocked the ball away from Lumpkin, then converted a layup for a 37-36 Dayton lead. After an offensive foul on Braggs, Dayton went ahead by three on two free throws by Hoskins.
''I knew they weren't going to quit when they were down,'' Brown said. ''Just like last year.''
It was back and forth the rest of the half, and Dayton took a 42-40 lead into the locker room. Akron was the only team previously to lead Xavier after 20 minutes.
The game started as if it could be another Musketeer blowout.
After UD opened the scoring on a Hoskins three-pointer, Xavier scored nine straight during a 15-2 run. XU's biggest lead came after a short turnaround jumper by Braggs made it 22-8 with 10:57 on the clock.
Dayton started the game 3-of-16
from the field and 1-of-10 from three-point range.
Xavier travels to New York for a game at Fordham on Saturday. Dayton plays Thursday night at Wright State.
XAVIER (91)
fg ft rb
min m-a m-a o-t a pf tp
Johnson 25 1-3 5-8 1-4 1 4 7
Williams 34 4-6 0-0 2-4 2 4 8
Braggs 37 8-12 3-4 1-8 2 2 19
Brown 37 12-21 0-0 2-3 7 3 29
Lumpkin 36 6-10 0-0 1-6 6 5 16
Anderson 4 0-1 0-0 0-0 0 2 0
Harvey 1 0-1 0-0 0-0 0 0 0
Posey 26 4-7 4-5 3-9 1 5 12
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TOTALS 200 35-61 12-17 10-34 19 25 91
_______________________________________________
Percentages: FG-.574, FT-.706. 3-Point Goals:
9-20, .450 (Brown 5-10, Lumpkin 4-8, Harvey 0-1,
Posey 0-1). Team rebounds: None. Blocked shots: 2
(Lumpkin, Braggs). Turnovers: 22 (Lumpkin 6,
Braggs 4, Brown 4, Johnson 4, Williams 3, Posey).
Steals: 6 (Brown 2, Braggs, Johnson, Lumpkin,
Posey).
DAYTON (98)
fg ft rb
min m-a m-a o-t a pf tp
Perryman 18 4-6 3-4 3-5 2 4 11
Turner 13 2-7 0-0 2-3 1 0 4
Ashman 39 9-12 2-2 4-7 0 3 20
Hoskins 39 7-16 13-17 1-7 7 3 30
Haughn 30 3-7 2-2 0-1 5 2 11
Horton 30 7-14 3-5 1-6 1 0 20
Beyina 22 1-3 0-0 0-3 1 4 2
Young 9 0-0 0-0 1-1 0 1 0
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TOTALS 200 33-65 23-30 12-33 17 17 98
_______________________________________________
Percentages: FG-.508, FT-.767. 3-Point Goals:
9-25, .360 (Turner 0-4, Hoskins 3-6, Haughn 3-6,
Horton 3-9). Team rebounds: 1. Blocked shots: 3
(Ashman 2, Hoskins). Turnovers: 14 (Hoskins 5,
Ashman 2, Beyina 2, Young 2, Horton, Perryman,
Turner). Steals: 8 (Horton 3, Hoskins 2, Ashman,
Perryman, Young).
__________________________________
Xavier 40 51 - 91
Dayton 42 56 - 98
__________________________________
Technical fouls: None. Officials: Joe Mingle,
Mike Kitts, Rich San Fillipo.