RALEIGH — Only in the unpredictable ACC does this happen.

A week after losing to a team near the bottom of the Atlantic Division standings, N.C. State demolished the first-place team in the division.

The Wolfpack defense fueled an unbelievable 37-13 rout of No. 7 Clemson Saturday at Carter-Finley Stadium, keeping the Wolfpack's once-flickering bowl hopes alive and sending the Tigers into their rivalry game with South Carolina seething with embarrassment.

"I really have no explanation for what just happened," N.C. State coach Tom O'Brien said.

O'Brien is not alone. Last Saturday, N.C. State dropped a 14-10 head-scratcher to a Boston College team that was tied for last in the division with Maryland.

Meanwhile, Clemson clinched its second division title in three years last Saturday and seemed on the verge of its first 10-win season since 1990.

By the second quarter on Saturday, the teams seemingly switched identities. N.C. State exploded for 27 points and rattled Clemson quarterback Tahj Boyd (21 of 34 passes, 238 yards, zero TDs, two interceptions) into his worst game of what has been a stellar season.

N.C. State's defense caused four turnovers, sacked Boyd five times and held the ACC's best offense without a touchdown for the game's first 58 minutes. It all added up to N.C. State's first win over the Tigers since 2003.

"It's incredibly disappointing and embarrassing how we played," Clemson coach Dabo Swinney said. "They certainly earned it and wanted it more than we did."

N.C. State (6-5, 3-4 ACC), which beat a top-10 team at home for the first time since 1998, needs to beat Maryland (2-9), now alone in last-place in the division, next Saturday at home to get back to a bowl game.

The Tigers (9-2, 6-2 ACC) will still play in the ACC title game Dec. 3 in Charlotte, but they will limp there instead of sprint.

Without freshman receiver Sammy Watkins, who sat out with a shoulder injury, Clemson couldn't get its high-powered offense going. The Tigers led the ACC with 37.1 points per game and 478.1 yards per game before Saturday.

N.C. State linebacker Terrell Manning (nine tackles) and defensive end Art Norman (2.5 sacks) terrorized Boyd and held the Tigers to 86 total yards in the first half as the Wolfpack built a 27-3 lead.

Manning and Norman combined on the key play to ignite the Wolfpack run. Down 7-3, Norman sacked Boyd at Clemson's 10-yard line, which Manning picked up and advanced to the 6.

Two plays later, N.C. State quarterback Mike Glennon hit receiver Jay Smith on a 7-yard touchdown for a 14-3 advantage at 10:33 in the second quarter.

On Clemson's next series, offensive coordinator Chad Morris called a double-reverse with Boyd handing off to receiver Adam Humphries, who immediately tried to give it to running back Mike Bellamy. The second handoff was botched and N.C. State had the ball on Clemson's 18.

"After the first couple of turnovers, I could tell they were rattled and once we got going, we didn't stop," Manning said.

N.C. State had to settle for a 21-yard field goal after Bellamy's fumble but still found 10 more points before the end of the half.

After another three-and-out by Clemson's offense, T.J. Graham's 34-yard punt return gave N.C. State the ball on Clemson's 11, which Tony Creecy soon turned into a 4-yard touchdown run.

Sade tacked on one more field goal, a 32-yarder, before the end of the half, to make it 27-3.

N.C. State's defense, which shut out North Carolina two weeks ago and allowed only 14 points in a loss to Boston College last week, set the tone in the second half with a fourth-down stand on Clemson's first possession of the second half.

Manning and Audie Cole forced a scrambling Boyd out-of-bounds and any hope of a Clemson rally - as it did last week against Wake Forest and earlier in the season at Maryland - was muted.

Boyd threw two red-zone picks in the third quarter, one to cornerback David Amerson at the 1, and another to Brandon Bishop in the end zone.

It was N.C. State's first win over top-10 team since beating Florida State in 2005. More importantly for N.C. State, it put it back on track for a third bowl trip in four years.

"We don't want to be home in December," said senior tight end George Bryan, who caught an 11-yard touchdown.

With a win over Maryland next week, the Wolfpack won't have to be.

Giglio: 919-829-8938