Jordan Woodard had 16 points and a steal that set up Buddy Hield for a layup to give
Sooners Coach Lon Kruger became the second coach to take four schools (Kansas State, Florida and UNLV) to the round of 16. Third-seeded Oklahoma (24-10) will play
The Flyers (27-9), who started in the First Four at home, came up a victory short of their second straight trip to the Sweet 16 as an 11th seed.
Hield scored 15 points, including a layup off a feed from Woodard at 5:56 that made it 57-56. Oklahoma rallied with its defense, holding Dayton scoreless for 9:04 and without a basket for 10:32 in the second half.
Scoochie Smith led Dayton with 16 points.
Dayton fell behind by double digits early as the Sooners knocked down three straight threes to start the game. Playing for the sixth time in 10 days, it was fair to wonder if the Flyers were finally running out of energy, even while getting a boost by another partisan and passionate crowd at Nationwide Arena.
The Flyers steadied themselves in the first half and they were the stronger team to start the second half. A 9-0 run, capped by a beat-the-shot-clock 3-pointer by Darrell Davis at 13:40 put Dayton up 46-40 and got OU to call a timeout. It didn't immediately help. Dyshawn Pierre knocked down another 3 and Dayton had its biggest lead, 49-40.
A 3-pointer by Bobby Wehrli made it 52-45 at 11:51 and the Flyers were and their fans were rocking. Then Dayton went cold.
The Sooners extended their defense, getting into the passing lanes for two straight steals that led to two straight fast-break hoops.
The Sooners are past the first weekend of the NCAA tournament for the first time since 2009 when Blake Griffin and Co. lost the regional final to Carmelo Anthony and eventual national champion Syracuse in Buffalo.
It must have been a similar feeling for Oklahoma fans on Sunday, watching the Sooners face a team playing close to campus with fans making it sound a road game for OU.
The Sooners started strong from 3-point range, hitting seven of their first nine to take a 29-17 lead.
Dayton extended its zone, forced six turnovers and reeled off 15 straight points with Davis' 3-pointer giving the Flyers their first lead, 32-29, and sending their fans into a frenzy.
Davis finished with 15 points on five 3-pointers.
The Sooners went to the half with a 34-32 lead, with Frank Booker hitting three 3-pointers.
Eddie Sutton is the only other coach to get to the round of 16 with four schools.