In college basketball’s midmajor leagues, winning the conference tournament is often the only dependable way for a team to secure an N.C.A.A. tournament bid.

But even before the Bellarmine men’s team beat Jacksonville, 77-72, in the ASUN Conference championship game on Tuesday, it had no shot at participating in the national tournament.

Bellarmine, a private, Catholic university in Louisville, Ky., with about 2,400 undergraduate students, reclassified to Division I from Division II last season. Under N.C.A.A. rules, it must complete a four-year transition period to ensure it can handle rule changes and subsist at the higher level, during which time it is ineligible for the national tournament.

So while the Knights had home-court advantage and the support of their fans on Tuesday at Freedom Hall, they also had the backing of Jacksonville State in Alabama. With Bellarmine precluded from receiving the automatic bid to the N.C.A.A. tournament, the spot instead fell to Jacksonville State, despite its loss to Jacksonville in the ASUN tournament semifinals, because Jacksonville State won the regular-season championship. This will be the first N.C.A.A. tournament the Gamecocks have played in since the 2016-17 season.

For the Knights, playing any games beyond the conference tournament may have seemed unlikely after an 0-5 start, though the losses were to good teams. Bellarmine Coach Scott Davenport said in a postgame news conference that the “leadership kicked in” from team captains at that point in the season.

Davenport said the possibility of his team playing in the National Invitational Tournament was “totally out of any control” because it is run by the N.C.A.A. He mentioned the College Basketball Invitational, which the Knights played in last year, as a postseason possibility.

“I don’t know how any coach at any level, any sport could be more proud than I am,” he said.

Bellarmine won the ASUN tournament with help from the 3-point shot, a key component of its success in Division II: The Knights shot 40.1 percent from 3-point range during the 2019-20 season, when they closed their Division II tenure by earning a N.C.A.A. tournament bid before the coronavirus pandemic forced its cancellation. And they made a program-best 312 3-point shots in 2016-17, when they made one of their four Division II Final Four appearances of the 2010s.

On Tuesday, the Knights shot 12 of 25 from long range. CJ Fleming shot 4 of 11 from 3-point range and led all scorers with 27 points. Dylan Penn added 22 points on 9-of-15 shooting from the field and won the tournament’s Most Valuable Player Award.

The impossibility of reaching the N.C.A.A. tournament didn’t dampen the excitement of Bellarmine fans, who rushed the court after the final buzzer.

“I looked back at the bench and saw all them coming,” Fleming said. “I turned around and we were just getting swarmed. Such an awesome feeling.”

Last year’s ASUN men’s tournament final was also dogged by the specter of the transition period. Liberty received the conference’s automatic bid to the N.C.A.A. tournament before tip-off because of North Alabama’s ineligibility, then it won the game anyway.

Other teams have also missed out on the national tournament because of the transition period. Just last season, the California Baptist women’s program had an undefeated run to the Western Athletic Conference tournament title, but could not participate in the N.C.A.A. tournament.

Along with Jacksonville State, Bryant, Delaware, Wright State, No. 1 Gonzaga and South Dakota State also clinched automatic bids on Tuesday.

In Bryant’s game, a festive atmosphere bubbled over in the second half as the home team dominated the Northeast Conference tournament championship. The victory over Wagner sent the Bulldogs to their first N.C.A.A. tournament since they moved to Division I in 2008, but it will also be remembered for a delay of more than 20 minutes because of a fight near the two student sections with Bryant leading by 36 points with less than five minutes left.

The police at the Chace Athletic Center, Bryant’s on-campus arena in Smithfield, R.I., escorted fans, including most of the Wagner contingent, from the stands. Wagner’s Will Martinez unsuccessfully tried to get into the bleachers and was ejected for leaving the bench area.