NASHVILLE, Tenn. (AP) -- First, the 21st-ranked Vanderbilt Commodores lost the Southeastern Conference's best shot blocker to injury. Then they lost a 16-point lead on their own floor.
The Commodores announced just before tipoff Wednesday night that Luke Kornet will miss up to six weeks with a torn medial collateral ligament in his left knee. Minus the junior, they still jumped out to a big lead against Dayton.
But without their most physical player, the Commodores couldn't hold on and lost 72-67.
Stallings said Kornet was hurt in practice Monday.
"So you don't have a big chance to change too much, and obviously we were hoping to win this game, then we have some time to adjust and figure out what makes sense for us going forward," Stallings said. "We weren't able to do that."
Kendall Pollard scored a season-high 21 points for Dayton. Scoochie Smith added 13 points, and Steve McElvene added 10 as Dayton shot its way back into the lead despite just seven points from leading scorer Charles Cooke.
The Flyers (7-1) now have beaten three teams from the Power 5 conferences this season, with previous wins over Alabama and Iowa. They have won two straight since being routed 90-61 by Xavier.
"Certainly a terrific win for our team," Dayton coach Archie Miller said.
Wade Baldwin IV and Damian Jones scored 18 apiece for Vanderbilt (6-3), which hit just two of its final 10 shots. Matthew Fisher-Davis and Riley LaChance each added 11 points.
"We got to play harder," Stallings said. "We came out the start of the second half and I mean literally on defense we were walking around. Literally."
Vanderbilt took its biggest lead at 38-22 off a 12-2 run. Darrell Davis answered by scoring the next eight points starting a 23-6 run that spanned halftime and put Dayton ahead 45-44 early in the second half on a layup by Cooke.
The Commodores missed eight of their first nine shots in the second half before Jones threw down a one-handed dunk and hit the free throw to put Vandy back up 47-45 with 13:50 left.
But Pollard hit just the fifth 3-pointer of his career with 44 seconds left to help seal the upset for Dayton, matching the Flyers' biggest lead. Smith missed two free throws with 36 seconds left, and Fisher-Davis hit a 3 from the left corner with 25 seconds left to pull Vandy within 69-67.
Baldwin missed a layup for Vandy, and the Flyers hit three of four free throws in the final 12 seconds.
Vanderbilt: The Commodores were leading the SEC by holding opponents to 34.6 percent shooting, including 29.1 percent from 3-point range. But Dayton shot 59 percent in the second half (16 of 27). ... Stallings said freshman guard Camron Justice is out until sometime in January with an injured groin. ... Vandy hit just 6 of 25 in the second half.
Dayton: Dayton has won 12 of 15 against the SEC and is 28-11 against Power 5 schools over the past nine years. ... Miller now is 22-7 in December.
The Flyers outrebounded Vanderbilt 41-31, including a 15-7 edge on the offensive glass. That led to a 17-2 scoring edge in second-chance points.
"It's unacceptable for a Top 25 team to lose two games in a row, especially losing here on our home court like that," Baldwin said.
Vanderbilt gets a 10-day break before hosting Wofford on Dec. 19. Dayton hosts Chattanooga on Saturday.