Kendall Pollard scored 17 points, and the Flyers used every bit of their home-court advantage on Wednesday night, rallying for a 56-55 win over Boise State in the First Four.
"They were given a really hard deal coming in here tonight," Dayton coach Archie Miller said of Boise State.
Now the Flyers (26-8) get to stay in the Buckeye state — taking on sixth-seeded Providence on Friday in Columbus.
In the first game of the night, the three-pronged offence of Lucky Jones (21 points), Rodney Pryor (20) and Marcquise Reed (19) powered Robert Morris back from a 13-point second-half deficit to an 81-77 victory over North Florida.
The Colonials (20-14), who won the Northeast Conference Tournament to get into the field as a 16, now meet top-seeded Duke in the second round on Friday in Charlotte.
"I like our chances," Jones said. "It's a team game, no matter who they have on their team, no matter how many TV games they have. I love Robert Morris. We just gotta go out there and believe in ourselves, have confidence, have fun and see what happens."
Dayton became the first team since 1987 to play an NCAA Tournament game on its home court, an anomaly resulting from the city hosting the opening games. The Flyers went 16-0 at home during the regular season and have won 22 straight at its arena, the seventh-longest active streak in Division I.
The Flyers trailed by as many as 12 points in the first half and by seven with 3:43 to go. But with decidedly partisan crowd roaring everything the Flyers did, Dayton closed with a 10-2 run.
Derrick Marks' leaning 3-pointer at the buzzer was far off the mark, finishing it off. Marks had 23 points on 10-of-21 shooting.
The Broncos had already snapped San Diego State's 29-game home-court streak this season, and came up just short of another big road win. The Broncos missed seven of their last eight shots.
Jordan Sibert's two free throws tied it at 53-53 with 1:02 left, and his long 3-pointer gave the Flyers a 56-55 lead with 34 seconds to go.
After Montigo Alford missed a driving bank shot, and Pollard got the rebound, he was fouled and missed both free throws with 14 seconds left, giving the Broncos a final shot. Marks leaned into Kyle Davis on the final attempt, which missed everything.
In the first game, Reed — a freshman — drove the lane and spun in a left-handed layup and was fouled with 3:49 left to snap a tie. He missed the free throw, but Jones was there to tip in the miss for a 70-66 lead.
Pryor then added a 15-foot jumper and Kavon Stewart hit a free throw to push the lead to seven with 2 minutes left.
The Ospreys got within 78-76 with 10 seconds left, but Stewart made two more foul shots. With the lead at three and less than a second left, Jones made a free throw to clinch it.
Beau Beech finished with 28 points for the Ospreys (23-12), champs of the Atlantic Sun Tournament who were making their first trip to the NCAA Tournament.
Dayton: The Flyers wore something other than their white jerseys at home for the first time since 2010, when they added a black jersey. Technically, they were the visitors on their home court.
Boise State: During the season, the Broncos made an average 8.8 3-pointers per game, which ranked 16th in Division I. They went only 6 of 20 against the Flyers.
Robert Morris: The Colonials were making their eighth trip to the NCAA, but first since 2010. Their last trip was brief, but memorable. The 15th-seeded Colonials nearly knocked off No. 2-seeded Villanova in the opening round in Providence. They led 55-47 with 4:19 left, but mistakes down the stretch resulted in a 73-70 overtime loss.
North Florida: For financial reasons (hefty guarantees to play at bigger schools) the Ospreys played 13 of their first 16 games on the road. They travelled to nine states and Mexico this season.
Dayton: The Flyers will play sixth-seeded Providence on Friday in Columbus, Ohio.
Boise State: The Broncos lose Marks and senior Igor Hadziomerovic.
Robert Morris: Top-seeded Duke (29-4) on Friday at 7:10 p.m. in Charlotte.
North Florida: The three top scorers are back, with the major loss Nesbitt, a 6-6 senior.
AP Sports Writer Joe Kay contributed to this story.
Follow Rusty Miller on Twitter: http://www.twitter.com/RustyMillerAP