PHILADELPHIA — The rebellion of St. Peter’s — the unexpected March uprising by a hardcourt underdog that felled some of college basketball’s most fabled powers — ended in Philadelphia on Sunday.

No team this year had stunned the N.C.A.A. men’s tournament more. No team ever, in fact, had come so far from such a dismissive start. But North Carolina, dented by an uneven regular season that gave way to the kind of play that has long placed it among the sport’s elite, made short work of St. Peter’s and vanquished its aspirations, 69-49.

North Carolina, which had scored at least 93 points in two of its games in this tournament, did not fully erupt against a defense that had powered the Peacocks to a 10-game winning streak, the longest active run in the nation entering Sunday’s matchup. St. Peter’s, though, had few answers for a supersized Carolina team that stormed up and down the court, finding open lanes and clean shots amid a cascade of Peacocks miscues.

The final buzzer in Philadelphia on Sunday night secured the Final Four matchups, which will be contested on Saturday in New Orleans: Villanova will play Kansas, and North Carolina will meet Duke, the first N.C.A.A. tournament showdown between the two Tobacco Road rivals. The title game will be held next Monday.

The women’s Final Four will be set by Monday night, with the national semifinals played on Friday and the final on Sunday in Minneapolis.

The men’s games will be played beneath a spotlight that, until Sunday evening, had so often belonged to the Peacocks and their coach, Shaheen Holloway.

Just two weeks ago, St. Peter’s, a Jesuit university of 2,637 students in Jersey City, N.J., was a pick of the devout or the delusional, a favorite of the inattentive or the idealistic. The Peacocks were not in the field as a team that had steamrollered blue-blood opponents, had assembled a perfect season or had enough cachet to make the selection committee think twice about leaving them out of the tournament.

No, the Peacocks qualified automatically because they had won the Metro Atlantic Athletic Conference tournament by beating Monmouth. They were promptly relegated to something just more prestigious than a play-in game: the 15th seed and, this year, a date with Kentucky, the No. 2 seed with a coach whose annual salary exceeded the expenses of the entire St. Peter’s athletic department.

“Rightly or wrongly, they’re in that group in the fourth quadrant, the 13th through 16th seed lines,” Tom Burnett, the selection committee chairman, said in a courtside interview before Sunday’s game. “They’re just another one of those conferences, and we’re kind of just waiting for the champion, you know, to be designated. After that, it’s kind of out of our hands.”

No M.A.A.C. team had won an N.C.A.A. tournament game since 2009, when Siena beat Ohio State. But on a Thursday in Indianapolis, St. Peter’s turned a night of skillful shooting, including 18 points from the free-throw line, into a victory over Kentucky. Then came a second-round win over Murray State.

On Friday night in Philadelphia, where St. Peter’s beat mighty Purdue, the Peacocks became the first 15th-seeded team to reach the men’s tournament’s round of 8. (The competition, which began with eight teams in 1939, first began a seeding system in 1979, when the field featured 40 teams.)

“With hindsight, we’ve all learned what we’ve learned,” said Burnett, who is also the commissioner of the Southland Conference, whose champion, Texas A&M-Corpus Christi, was seeded 16th and lost a play-in game to Texas Southern. “It’s probably relative to what other people were thinking about St. Peter’s before their tournament and they won and all that.”

St. Peter’s, which had thrived with menacing defense, a sterling duo of free-throw shooters and a knack for rebounding, knew it would next face one of the most prestigious programs in college basketball, either North Carolina or U.C.L.A. Between them, they had amassed 17 N.C.A.A. championships; St. Peter’s, in its history, had not won an N.C.A.A. tournament game until this month.

The North Carolina team that emerged from the round of 16 had, as recently as mid-February, hardly seemed like one of the finest ever to rise out of Chapel Hill. There had been humiliating regular-season losses to Kentucky, Miami and Wake Forest. Duke swaggered onto the Tar Heels’ home court in February and won by 20, and then North Carolina lost to Pittsburgh.

A team that had sometimes seemed adrift, though, never lost again in the regular season and capped it by making the drive over to Duke and upending Mike Krzyzewski’s final game at Cameron Indoor Stadium. The Tar Heels stumbled in the Atlantic Coast Conference tournament, but arrived at Wells Fargo Center on Sunday evening having lost just once since Feb. 19. They had beaten Baylor, the reigning men’s champion, in overtime in the N.C.A.A. tournament’s second round and then hounded U.C.L.A. out of Philadelphia.

And their first-year coach, Hubert Davis, knew something about facing a double-digit seed deep in the N.C.A.A. tournament: As a player for North Carolina in a regional final in 1991, he scored 19 points to help the Tar Heels escape Temple.

But in an arena saturated with white and shades of blue — the colors of St. Peter’s and U.N.C. (and the N.C.A.A.’s March Madness branding) — and thunderous before tip off, North Carolina galloped from the start and opened with a 9-point run that mixed free throws and three layups. By the time St. Peter’s scored its first basket, a 3-pointer by Fousseyni Drame, more than four minutes had passed, and the Peacocks had missed six shots.

Both teams struggled with easy shots in the early going, with one ball after another making the net wiggle but no more. And as the Carolina defense swarmed to guard a first-half lead that swelled to as many as 21 points three times, the St. Peter’s men seemed to dribble all the more emphatically, the ball thudding from the floor just a little louder.

Dribbling, though, does not solve shooting. Even a dunk attempt by Daryl Banks III, the leading scorer for St. Peter’s this season, missed.

As if to assert that Carolina was performing more of a smothering than a mere victory, Armando Bacot powered into the paint on the court’s other end, lifted off and crashed a dunk through.

By halftime, when North Carolina led by 19 points, the Peacocks had not made even a quarter of their field goal tries. They had sunk a lone 3-pointer, while North Carolina had hit four, and St. Peter’s 19 rebounds were nearly exceeded, alone, by Bacot’s 15.

The balm for St. Peter’s, if there was one, had been the periodic trips to the free-throw line, the strip that helped give rise to some of this month’s improbable feats. But the Peacocks had not had a player reach the line until more than 14 minutes into the game, when Leaky Black fouled Drame.

The St. Peter’s offense started to find a measure of rhythm in the second, when Drame hit three baskets in 55 seconds. North Carolina, which was playing to reach its first Final Four since 2017, saw its own shooting and scoring paces slow. The Tar Heels, though, could afford that: St. Peter’s did not match North Carolina’s first-half points, 38, until Banks’s two free throws with 6 minutes 3 seconds left.

Long before, some Peacocks fans near the court had seized the sporting spirit of Philadelphia and begun to heckle U.N.C. The Tar Heels, one shouted, would never make it past Duke.

They will get a chance, though. They had downed the rebellion.

In New Orleans on Saturday, four teams that have won national titles will fight toward another. Back in Jersey City, St. Peter’s will still be searching, someday, for its fourth N.C.A.A. tournament win.