CHAPEL HILL, N.C. – Everyone needs a wake-up call every now and then.

Yes, even a No. 1 team that is a defending national champion riding a 19-game winning streak.

Clemson got its alert Saturday afternoon on a sun-splashed day against North Carolina at the same Kenan Stadium where the Tigers came up on the short end of a 21-16 verdict on their last visit here.

“Probably the worst game I’ve ever coached,” Clemson coach Dabo Swinney said last week.

Saturday’s visit went better.

Barely.

Clemson’s defense thwarted a two-point conversion with 1:17 remaining in the game and the Tigers held on for a 21-20 victory that extended its program-record winning streak to 20 games.

"When we had to make a play, we made it, and that's what winners do," Swinney said. "I know we're supposed to just show up and beat everybody by double-digits and all that, but this is college football."

Perhaps North Carolina provided a harbinger of things to come when the Tar Heels took the opening kickoff and promptly scored in four plays for a 7-0 lead – the first points the Tigers had allowed in the first quarter this season.

The game was a back-and-forth affair from there, rife with tense and tenuous moments and chock full of missed opportunities on both sides.

It harkened back to the days in the 1980s when these two teams regularly waged hard-fought, competitive slugfests that more often than not determined the Atlantic Coast Conference champion.

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Under first-year coach Mack Brown, North Carolina has rekindled some of that past glory, and that was evident Saturday.

The Tar Heels waged a gallant final effort, executing a 16-play, 75-yard drive that consumed 8:32 and pulled Brown’s club within a single point, 21-20 with 1:17 remaining. Brown opted to go for the two-point conversion and a potentially program-altering victory, but the Tigers’ defense was up to the task, with Xavier Thomas, James Skalski and Nolan Turner pouncing on freshman quarterback Sam Howell as he rolled to his right. Chad Smith also was in on the play that sealed the Tar Heels fate and perhaps the Tigers’ season.

"How about North Carolina -- what can you say about that group?" Swinney said. "They played with tremendous heart and tremendous effort and I knew that coming in. I told our guys they were good enough to beat us and good enough to beat anybody in this league."

It was a matchup that proved downright ugly for the much of the game, but Clemson gathered the gumption and guile to make some pretty plays when it mattered most, including:

► Sophomore quarterback Trevor Lawrence went 3-for-3 and rushed four times for 25 yards, including a 3-yard touchdown, on a 10-play drive that tied the game at 14 just 33 seconds before the half;

► Clemson’s defense posted back-to-back sacks by Isaiah Simmons and Tyler Davis to thwart a promising third-quarter drive by the Tar Heels;

► The defense came up huge again on North Carolina’s next possession, stonewalling third- and fourth-down efforts by the Tar Heels, with linebacker Simmons looming large on both stops.

► Tee Higgins was Clemson's key playmaker, with six receptions for 129 yards, including a 38-yard touchdown catch that provided what would turn out to be the winning score with 9:54 remaining.

But none were bigger than the two-point conversion with 1:17 left to play, allowing Clemson to remain atop the ACC standings and maintain its status as the odds-on favorite to capture a fifth consecutive ACC championship.

"I thought it was a really fun game," said Simmons, who led Clemson with 10 tackles. "What better situation could there be -- game's on the line, one play left? It was all on us. Those are the kind of games you dream about."

Clemson’s offense never looked completely sharp, nor did its defense. The Tigers had myriad penalties that were more the product of discipline rather than crowd noise.

Given the closeness of the game against a team that counts losses to Appalachian State and Wake Forest, Clemson (5-0, 3-0) may take a hit in the polls, potentially slipping from the No. 1 spot.

But there could have been valuable lessons gleaned from a mid-season wake-up call that still goes into the “W” ledger.

Given how it came about, Swinney may henceforth refer to this latest triumph as “the worst game I’ve ever won.”

It was close but no cigar for the Tar Heels and their inspired effort, tying for the closest they’d ever come to knocking off a No. 1-ranked team. It also was the Tar Heels' closest loss ever in 58 games all-time against Clemson.

“I told the players that we’re not into moral victories,” North Carolina coach Mack Brown said. “That can’t happen, because you’ve got to learn to win. . I told them in my 31 years of coaching, I’ve never been prouder of their effort, because if I’m a reflection of the way those guys fought tonight, then I’m very, very proud of that.”

This much is certain: if Clemson rides into another successful postseason, the Tigers won’t soon forget the afternoon they received a late-September wake-up call in Chapel Hill.