SAN DIEGO — The clock had barely ticked into St. Patrick’s Day when Paul Atkinson Jr. scored the game-winner on a putback layup with 1.4 seconds remaining in the second overtime to, crushingly, send Rutgers home.

It was the middle of the night in Dayton, Ohio, but Notre Dame was dancing, and Coach Mike Brey was smiling and hollering that there had better be Irish whiskey aboard the Fighting Irish’s flight to San Diego. The N.C.A.A. men’s basketball tournament had barely reached the starting blocks, with Notre Dame’s 89-87 win over Rutgers concluding the First Four games, but it had already hit an extreme emotional peak.

“If there’s a better game in the N.C.A.A. tournament, I’ve got to see it,” said Brey, who, in his 27th straight season as a Division I head coach, called it the best game he’s been involved with. “That was an unbelievable college basketball game.”

He added: “You notice Paul’s shot went in at 12:02 on St. Patrick’s Day. Maybe there was a little bit of karma there.”

Or, perhaps, not so much karma as much as Brey’s astute reflexes combined with a confluence of unique Ivy League conditions that conspired to send Atkinson to South Bend, Ind. Not only did the Ivy League call off its entire 2020-21 athletic season because of the pandemic, but it also does not allow redshirt seasons. So when Atkinson graduated from Yale last spring, his N.C.A.A. eligibility appeared to be graduating with him even though his senior season had been canceled.

So, in anticipation, Atkinson, a 6-foot-10 power forward, entered the transfer portal in October 2020, and the Fighting Irish boxed out more than a dozen other programs to secure his commitment four months later.

He hurt Rutgers all night, hitting 13 of 15 field goals en route to a game-high 26 points and snagging the biggest offensive rebound of the evening to set up the game-winning follow that advanced Notre Dame to play No. 6 Alabama at 4:15 p.m. Eastern on Friday.

“We felt we could throw it into him and he could score in the low post,” Brey said. “And he did.”

This is Notre Dame’s first N.C.A.A. tournament appearance since the 2016-17 season, so for both the Fighting Irish and Atkinson, who has averaged 12.8 points and 6.9 rebounds per game this season, it was an extra-special game.

Atkinson said his mind-set coming into the tournament simply was to “battle” for his teammates because “they haven’t been here, I haven’t been here, in a long time. And it’s potentially my last year so I just wanted to battle. A lot of people don’t get this chance.”

Fewer, still, get the survive-and-advance moment that Atkinson enjoyed.

“I haven’t felt like that in a long time,” Atkinson said of the blur after his game-winner. “It’s amazing. Bunch of cameras on you. Big spotlight, last game of the night. It’s amazing. Definitely got my teammates to cheer with. It’s just awesome. Got family up in the stands. Couldn’t ask for anything better.”

Not only is the Ivy League the only one of the 32 Division I men’s basketball conferences that does not award athletic scholarships, it also is the only league that does not permit graduate students to compete. It did make an exception for this school year because of the pandemic, but it did not do so until last February. By then, graduate students would have had difficulty compiling their applications before the admission deadlines.

And, by then, Atkinson had already told Notre Dame he would pursue a master’s in finance under the Golden Dome.

Combined, the canceled 2020-21 season and league policies have led to a talent exodus for Ivy League basketball. Patrick Tapé, who is starting for San Francisco this season as the Dons make their first N.C.A.A. tournament appearance since 1998, is Columbia’s career leader in field-goal percentage. He played last season at Duke before transferring to San Francisco. The former Columbia point guard Mike Smith helped Michigan reach a regional final last season. Jimmy Boeheim is playing for his father, Jim, at Syracuse after leaving Cornell. Ohio State gained Seth Towns, and Seton Hall welcomed Bryce Aiken last season. Each played at Harvard.

But the most talent, arguably, has been drained from Yale. Baylor started Makai Mason at guard in 2019 in his final season of eligibility, center Jordan Bruner played his final year at Alabama last season and Atkinson was an Ivy League Player of the Year in 2020.

So, as the Bulldogs prepared for their first-round N.C.A.A. tournament game against Purdue in Milwaukee on Friday, many of them were transfixed watching Rutgers-Notre Dame late Wednesday night and cheering for Atkinson, their good friend and former teammate.

“I was actually in the weight room doing some late-night recovery, rehab work and was watching on the TV,” the Yale captain Jalen Gabbidon said. “When it happened, I literally, like, screamed in the hotel. It’s funny seeing Paul have, like, 26 on national TV. We felt like he’s an incredible player. Obviously, we thought we were going to have our run in March Madness together the last time we were at Yale. So for him to come out here and win a game and being a key part of Notre Dame just brought me a lot of joy for him.”

Azar Swain, who set Yale’s career record for most 3-pointers made this season, waited to text his friend until later Thursday morning because he knew Atkinson’s phone would be besieged in the seconds after the wild game ended.

“Kind of like Jalen said, we’re all in this together,” Swain said. “It felt like we had a lot of things that we could have still accomplished together. Things happen, roads, things come to an end. Just super proud of him, super happy he’s able to shine in a moment like that because it’s been a long time coming for him.”

So call it karma, as Brey did. Or the luck of the Irish, given the corned-beef-and-sauerkraut kind of day it was as Notre Dame prepared to run through a late-afternoon practice here to prepare for the Crimson Tide.

Or, maybe, it’s simply a product of good, old-fashioned elbow grease; from Atkinson, to climb into position for the moment of his basketball life against Rutgers, and from Brey and the Irish, for doing what they needed to do to land him.

Whatever, short night, long flight, Notre Dame can’t wait to see what comes next.

“Did U.C.L.A. win in overtime last year against Michigan State in this game?” Brey asked. (Yes, the Bruins did on their way to the Final Four.) “Sunday night at my house, I said we’re going to try to channel U.C.L.A. And talk about coachable guys, huh? And so I’m going to damn sure convince them over the next 48 hours, or 36, that it’s our time.”

Billy Witz contributed reporting from Milwaukee.