DeMarr Langford Jr. swung the ball to the left wing for his older brother. Makai Ashton-Langford was wide open. He took a half second to gather himself before netting a 3-pointer.

A Conte Forum crowd of more than 6,000 erupted. So did Langford, who leapt in the air while screaming in jubilation following his brother’s make.

Only for a second, though. Then it was back to defense, where James Karnik immediately stole a Ryan Cormac pass, flipped on the accelerator and drew a foul on the fastbreak layup.

BC was riding a 13-2 run, beating up Notre Dame on the glass and Karnik was having the best game of his Eagles career. The Lehigh transfer had himself a first-half double-double and finished with 17 points and 13 rebounds. Fellow center Quinten Post chipped in 13 points and six boards.

And the Eagles out-rebounded Notre Dame, 37-28, in a 73-57 win—BC’s largest margin of victory over the Fighting Irish in program history.

“Tonight, it looked like varsity versus JV,” longtime Notre Dame head coach Mike Brey said of BC’s dominance inside. “And we got exactly what we deserve. Very impressed with how they’re playing and who they have.”

Notre Dame (3-4, 0-1 ACC) came into Friday having already faced three teams rated 61st or higher by KenPom. But the Fighting Irish were punched in the mouth by BC (6-3, 1-0).

Karnik, fittingly, delivered the first blow: a 3-pointer from the top of the arc.

The Eagles started the game on a 7-0 run. Meanwhile, Notre Dame missed its first six shots. BC was on its A-game defensively, defending the 3-point line particularly well. Langford noted postgame that the Eagles spent a good bit of time this week guarding drive-and-kick triples. It paid off.

Notre Dame was 4-of-15 from 3-point land in the first half. As well as BC played defensively in those opening minutes, the Eagles could have created even more of a cushion for themselves. That said, a couple of turnovers and missed shots in the paint allowed the Fighting Irish to quickly pull even.

Soon enough, Post got going, courtesy of a nice feed from Ashton-Langford that resulted in a two-handed flush from the 7-footer. He then made two trips to the line and converted all four free throws.

Notre Dame center Nate Laszewski and the backcourt pairing of senior Dane Goodwin and freshman Blake Wesley kept the Fighting Irish around. But a seven-point scoring spurt from College of Charleston grad transfer Brevin Galloway staked the Eagles to a 24-16 lead that would only continue to grow.

Galloway, who missed five games with a knee injury earlier this year, capped the momentous stretch by picking Ryan’s pocket and streaking down the court for a transition layup.

It wasn’t long before BC’s big men stole the show again. Karnik followed up a back-to-back offensive rebound putback with a faceup jumper in front of the 6-foot-10 Laszewski. Karnik had 11 points and 11 boards in the first half.

“I saw a big size opportunity,” Karnik said. “Typically, I always take the first kind of couple minutes to be a little cautious. … When I saw that they weren’t really calling anything, and I was free to crash the glass, I knew I had to take advantage of that.”

With just over a minute left in the period, Post drilled a 3-pointer to stretch BC’s lead to 12. The Eagles entered the break with a 10-point advantage.

Less than five minutes into the second half, the Eagles more than doubled that. The aforementioned 13-2 run featured a pair of TJ Bickerstaff 3-pointers as well as two Langford steals, the second of which resulted in a hard-earned bucket at the cup.

Karnik, who kissed a left-handed turnaround hook off the glass earlier in the run, put the cherry on top with a layup to put BC up, 52-29. Notre Dame answered with seven straight points, including five from Prentiss Hubb, a senior guard who registered a team-high 15 points.

“Anytime you got a veteran team like that, when you prepare for them, you’re gonna be worried a little bit,” Grant said. “’Cause they’re so experienced, and they’ve been through so many battles.”

But every time Notre Dame​​—shooting an improved 40% from the field in the second half—chipped away, the Eagles had a response. First it was Bickerstaff with a reverse layup. Then it was Ashton-Langford with an and-one in the lane.

Of course, it wouldn’t have been a Holy War without a little scuffle. Notre Dame forward Elijah Taylor got into it with Ashton-Langford after Ashton-Langford dove for a loose ball. Taylor, who at one point stood over Ashton-Langford, was slapped with a technical.

Ashton-Langford hit both of his free throws, and BC held on the final five minutes of play, maintaining its double-digit lead.

The Eagles, who were picked dead last in the ACC Preseason Poll, have their first league victory of the year and of the Grant era. And it was a big one.

Except Grant isn’t crowning anyone yet.

He knows the ups and downs that come with a new regime.

“I don’t really like to put the carriage in front of the horse,” Grant said. “I’ve been around first years, and you’re trying to build a foundation. We’ll take this win. We’ll try to build on it, but we know we gotta keep scratching and clawing.”