COLUMBUS, Ohio (AP) Facing a deficit and a fired-up Dayton team, fueled by its fans who packed the house again, Oklahoma went on lockdown.
A steal, then another, and then a third helped Oklahoma get the lead. A block by Buddy Hield put Dayton away.
Hield and Jordan Woodard led a second-half defensive surge as Oklahoma quieted the Flyers and their fans to advance to the second weekend of the NCAA Tournament with a 72-66 victory Sunday.
Coach Lon Kruger said it wasn't a matter of doing anything differently on defense - just doing it better.
''I thought we just took on some individual challenges a little bit within the team concept at that point,'' said Kruger, who 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 Michigan State on Friday at the East Regional in Syracuse, New York.
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.
''Yeah, just we just didn't make shots,'' said Jordan Sibert, Dayton's leading scorer on the season who had only seven points. ''Had nothing to do with us being tired. Just some shots didn't go in. It's basketball.''
Hield scored 15 points, including a layup after Woodard's steal to make it 57-56 with 5:56 left. Oklahoma never trailed again, slowly growing its lead from the line. Woodard had 16 points, including seven free throws in the final minute.
OU held Dayton scoreless for 9:04 and without a basket for 10:32 in the second half.
With the Sooners up four, Hield stuffed Darrell Davis as he went up for a fast-break layup after a turnover by Woodard. Hield said the turnover was his fault.
''I either had to foul them, don't let them get a shot up, but I made a good hustle play,'' the Big 12 player of the year said.
Scoochie Smith led Dayton with 16 points.
Dayton fell behind by double digits early as the Sooners knocked down three straight 3s 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.
''I think to start the game our legs weren't under us. But I did think we fought hard to get back. And I think the rest of the game was much more like ourselves,'' coach Archie Miller said.
The Flyers scored nine straight points to open a 46-40 lead on Davis' beat-the-shot-clock 3 at 13:40, prompting Oklahoma to call a timeout. It didn't immediately help. Dyshawn Pierre knocked down another 3 and Dayton had its biggest lead.
Davis finished with 15 points.
A 3 by Bobby Wehrli made it 52-45 at 11:51, but then the Flyers went cold.
During another timeout, the Sooners got after each other, and then they got after Dayton on the defensive end.
''We were all speaking up and we just trusted each other,'' Hield said. ''Shows a good sign for our team, trusting each other.''
The Sooners extended their defense, getting into the passing lanes for two straight steals that led to two hoops.
The Sooners are past the first weekend of the NCAA Tournament for the first time since 2009 when Blake Griffin and Co. lost to North Carolina in a regional final in Memphis, Tennessee.
The time before that was 2003, when Oklahoma lost to Carmelo Anthony and eventual national champion Syracuse in Albany, New York.
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 feel like a road game for OU.
''And you could tell when they hit big shots, when they hit 3s and got off our turnovers, and the crowd was going, but we just had to shut them down even though they got the lead late in the game, shut it down and play our ball,'' Woodard said.
Eddie Sutton is the only other coach to get to the round of 16 with four schools (Oklahoma State, Kentucky, Arkansas and Creighton), but his early trips to the Sweet 16 came before the tournament expanded to 64 teams. ... Dayton doesn't have a player bigger than 6-foot-6, but usually holds its own on the boards. Not against Oklahoma. The Sooners outrebounded the Flyers 35-23.
Oklahoma gets the Spartans for a spot in the Elite Eight.
Dayton looks toward next season and hopes it can keep Miller, 36, who is 90-47 in four seasons with the Flyers.