Notre Dame running back Kyren Williams, left, holds off North Carolina linebacker Jeremiah Gemmel during the second half in Chapel Hill, N.C., on Friday. (AP photo)

CHAPEL HILL, N.C. (AP) — Ian Book kept No. 2 Notre Dame’s offense moving while the Fighting Irish defense locked down Sam Howell and No. 25 North Carolina’s potent offense for the final three quarters in a 31-17 victory on Friday.

Book threw for 279 yards and a score and ran for 48 yards for the Fighting Irish (9-0, 8-0 ACC, No. 2 CFP), using his mobility and elusiveness to keep plays alive as both offenses frequently faced long fields.

Receiver Ben Skowronek got Notre Dame its first lead with his 13-yard run around the right side midway through the third quarter. Kyren Williams ran for 124 yards — including a 47-yarder with 5 1/2 minutes left as the Irish burned clock to seal the win.

Williams closed that drive with his second rushing TD, a clinching 1-yarder with 1:20 left that kept the Fighting Irish alone atop the ACC standings ahead of No. 4 Clemson and No. 10 Miami.

More impressively, though, was a defensive effort that forced Howell and the high-scoring Tar Heels to work for every gain after the opening quarter.

UNC (6-3, 6-3) sprinted to touchdowns on its first two drives, but Notre Dame surrendered only one field goal from there. The Tar Heels came in averaging 43 points and 563 yards, yet they were unable to buy time for Howell to push downfield.