CHAPEL HILL, N.C. — If Bill Belichick were still in New England, still helming a team he had coached for a quarter century, when he won six Super Bowls, he could have shrugged off Monday’s debacle against TCU as just a hiccup on a long road to somewhere better, answering his critics with his now ubiquitous retort: on to the next game.

In Chapel Hill on Monday, with a sellout crowd eager to get its first glimpse of a new era of North Carolina football under the tutelage of one of the game’s all-time greats, what happened couldn’t be shrugged off so easily.

Belichick’s Tar Heels were embarrassed, with TCU rolling to a 48-14 win in which UNC didn’t simply look like the lesser team, but one that often appeared unprepared for the moment.

“We’re better than what we were tonight, but we have to go out there and show that and prove it,” Belichick said. “Nobody’s going to do it for us. We’re going to have to do it ourselves, and that’s what we’re going to do.”

Through the first drive of Belichick’s tenure as a college coach, everything had gone right.

Crowds filled the bars and restaurants along Franklin Street in Chapel Hill hours before kickoff. A pregame concert, headlined by country star and UNC alum Chase Rice, set the stage for a star-studded event. Michael Jordan, Lawrence Taylor and Mia Hamm were in attendance as the Belichick era at North Carolina finally kicked off.

And then the Tar Heels delivered a flawlessly executed 83-yard touchdown drive, and the packed house at Kenan Stadium exploded.

This was the dream when UNC shocked the college football world by landing Belichick, and suddenly Belichick’s promise of bringing a national championship to a program that hasn’t won an ACC title in more than half a century felt plausible.

Then, TCU delivered one cold dose of reality after another, and by midway through the third quarter, after Devean Deal’s scoop-and-score on Gio Lopez’s fumble put the Horned Frogs up by 34, the once-frenetic stands emptied and the hope for something magical in Chapel Hill seemed a distant memory.

“They outplayed us, outcoached us, and they were just better than we were tonight,” Belichick said. “That’s all there was to it. They did a lot more things right than we did.”

Belichick turned over the bulk of North Carolina’s roster in one offseason, bringing in 70 new players — nearly half of whom arrived after spring practice. The transformation of the roster, along with Belichick’s famously guarded approach to the media, meant few outside of North Carolina’s locker room had a clear vision of what this squad would look like.

By the time the bludgeoning was over, the mantra from the Tar Heels was that this performance hardly showcased what they had seen on the practice field for the past six weeks.

“I thought we were prepared for the game,” UNC backup quarterback Max Johnson said. “We prepared for a week and a half for TCU specifically, but we’ve been working on our fundamentals for a year now. We need to do a better job executing.”

After the opening touchdown drive, North Carolina went three-and-out on five of its next six drives. Lopez went more than two hours of real time between completions. UNC failed to convert its first six third-down tries, and Lopez threw a pick-six late in the first half that seemed to be the last gasp for the Tar Heels. The defense was equally catastrophic. TCU racked up 542 yards of total offense and ran for 258 yards, including a 75-yard scamper by Kevorian Barnes, and the Heels missed one tackle after another.

“Too many three-and-outs, too many long plays on defense, two turnovers for touchdowns. You can’t overcome that,” Belichick said. “We just can’t perform well doing some of the things we did. We’ve got to be better than that. We had too many self-inflicted wounds we have to eliminate before we can even worry about addressing our opponent.”

Johnson replaced Lopez, who left after his sack-fumble because of a lower-back injury. Johnson delivered a touchdown drive that offered some spark of life for the Heels’ offense. Belichick said it was unclear whether Lopez would play Saturday at Charlotte, but he left open the possibility that the QB competition could be reopened.

“We’ll see how Gio is,” Belichick said. “Max came in after being off for a long time and hung in there and made some plays in a tough situation. We’ll take a look at it and see where things are at and go from there. It’s too early to tell now.”

Before the game, Belichick spent nearly half an hour on the field watching both teams warm up. He chatted with dignitaries and appeared to bask in the moment, but the magic quickly evaporated.

The 48 points scored by TCU in Belichick’s first career game as a college coach are more than his teams allowed in any of his 333 NFL games, and for as much as he had worked to sell North Carolina as “the 33rd NFL team,” Monday’s disaster felt like a reminder that, regardless of his success in the pros, this was new territory.

His response to the loss, however, was largely in line with what fans have come to expect of the understated coach — simple, succinct and emphatic.

“We’ve got a lot of work to do,” he said. “We’ll get at it.”

For a fan base that had waited nine months for this moment, however, it could be harder to turn the page. Belichick never promised a quick fix, but there were reasonable assurances that this team would play with physicality and fundamentals, that UNC wouldn’t be outcoached or outschemed.

By halftime Monday, the veil had been lifted. Belichick has six Super Bowl rings, but this was a bigger job than perhaps any he had assumed before.

The excitement that reached its apex after the opening touchdown drive perfectly showcased what this experiment could look like. The question now is whether UNC’s reality will match the dream or if Belichick’s first drive as a college coach will be remembered as the pinnacle of his tenure here.

“Don’t lose hope,” Johnson said. “We’re going to continue to put our best foot forward, continue to work and trust in each other.”