DAYTON, Ohio — UNO’s dream season ended in heartbreaking fashion Tuesday night.

In an otherwise well-played game that looked nothing like the typical NCAA tournament First Four encounter between No. 16 seeds, the Privateers lamented the kind of mistakes they usually did not make during a breakthrough season, losing 67-66 to Mount St. Mary’s at University of Dayton Arena.

A couple of mental breakdowns did not help, either.

The Mountaineers’ Chris Wray intercepted Erik Thomas’ long inbound pass for Michael Zeno with 2.9 seconds left and ran out the clock, leaving the Privateers one basket short of advancing to face No. 1 overall seed and defending national champion Villanova on Thursday in Buffalo, New York.

“I had it my head that we were going to win, and that’s all I could think about,” senior guard Christavious Gill said. “I was in disbelief for the first five minutes after the game, then it all sank in and hit me at once.”

UNO, which had not made the NCAA tournament since 1996, finished 20-12. Mount St. Mary’s (20-15) moved on for the second time in three First Four appearances.

A decision by coach Mark Slessinger to let Mount St. Mary’s play out its final possession instead of fouling will be a point of discussion for a long time. UNO’s Nate Frye had just hit a pair of free throws to cut the deficit to 67-66 with 34.2 seconds left.

After beating UNO’s pressure to get the ball across midcourt, the Mountaineers used all of the shot clock. The Privateers came up with a stop, but there were only 2.9 seconds left when Thomas grabbed the rebound and called a timeout, forcing UNO to try to go the length of the court and score with almost no time.

“They didn’t have many guys on the floor that were poor (free throw) percentage guys,” Slessinger said. “We felt pretty good about late-clock execution. We’ve done it two, three times this year to either put it overtime or get the win. … I felt like we could get a stop and get a shot on the other end. It’s just unfortunate we didn’t get the shot.”

If they had, it likely would have gone in. Both teams shot better than 50 percent as UNO tried to counter Mount St. Mary’s hot 3-point shooting with dominance inside. The Mountaineers sank 10 3-pointers in 19 attempts, while the Privateers outscored them 42-22 in the paint, repeatedly driving to the basket for easy shots in the second half.

Poor defense was where the Privateers felt they let the game get away. Mount St. Mary’s guard Junior Robinson, the smallest starter in Division I at 5-foot-5, scored a game-high 23 points on 7-of-10 shooting, knocking down open looks, penetrating past defenders and finding teammates for wide-open shots.

After UNO took its first lead, at 64-63, since it was ahead 10-7 early on two Gill free throws with 1:48 left, Robinson scored on a floater after almost having the ball stripped. The Mountaineers held on from there.

“He’s a heck of a player,” Gill said. “I’m short myself, but he was amazing tonight. It was hard to catch up to somebody as fast as you or even faster. We were late on ball screens, and that ended up hurting us at the end.”

Frye scored 12 early points in the second half and finished with a team-high 18. Thomas, the Southland Conference Player of the Year, added 12 but did not score in the second half.

Still, his lack of scoring was no real factor. UNO hit 16 of 24 shots in the second half as the Mountaineers concentrated on stopping him.

Defense was the issue.

“We got away from some things that made us successful,” Frye said. “One is just simply guarding. I think they shot 53 percent, and that’s not something we do. They made way too many 3s.”

UNO also lamented not taking care of the boards in the first half. The Privateers were more than plus-3 in rebounding margin entering the game, and the Mountaineers were almost minus-8, but UNO got outrebounded 18-16 in the first half before winning that battle 28-25.

“We had a slow start, and that really hurt us,” Thomas said. “And once we got our groove back, we weren’t able to finish the game out.”

UNO trailed by 11 late in the first half but closed with a 10-2 run thanks to Thomas, who came up with two steals and converted both into layups. The Privateers had a chance to tie the score at 31 on their last possession, but Tevin Broyles missed a 3-pointer with 1 second left. UNO took seven 3s in the first half, hitting only one, and finished 1 for 9.

Mount St. Mary’s was much more successful from long range, with Robinson and Miles Wilson combining to hit their first four. That set the tone.

“I wanted to play Villanova so bad,” Frye said. “But things happen for a reason.”