Jacksonville, FL (SportsNetwork.com) - Right when North Carolina appeared to be on cruise control, pesky Harvard was at it again in the NCAA Tournament.

Siyani Chambers' four-point play had just given the Crimson their first lead with just over a minute remaining, but his next shot from beyond the arc helped put the Tar Heels ahead for good.

Justin Jackson's go-ahead fastbreak dunk with 23 seconds remaining lifted North Carolina to a 67-65 victory over Harvard in a second-round game in the West Region Thursday night.

The Tar Heels (25-11) squandered a 16-point second-half lead.

Chambers nailed his straightaway 3-pointer while being fouled on the arm by Marcus Paige with 1:15 on the clock. He sunk the subsequent free throw for a 65-63 Harvard edge.

Jackson knocked down a jumper at the other end and Chambers was off the mark on a deep 3, leading to a Tar Heels run-out. J.P. Tokoto secured the rebound and outletted to Paige, who hit Jackson with a right wing bounce pass for the easy two-handed dunk and a 67-65 UNC cushion.

Chambers then missed another 3, this time from the right wing, and Kennedy Meeks was fouled going for the rebound. He missed the front end of a 1-and-1, but Wesley Saunders' potential go-ahead 3-pointer in the waning seconds ricocheted off the glass and clanked off the front of the rim.

"It's the luckiest I've ever felt after a basketball game in my entire life," Tar Heels coach Roy Williams said. "I'm thrilled that we're still here and we're still playing."

Jackson finished with 14 points, Paige posted 12 points and six assists and Meeks added 10 points and eight boards for the fourth-seeded Tar Heels, who No. 5 seed Arkansas in the third round Saturday.

The Razorbacks edged 12th-seeded Wofford 56-53 later Thursday.

The Crimson (22-8) took advantage by tallying 29 points off 17 UNC turnovers.

Saunders netted 26 points and Chambers put in 13 for 13th-seeded Harvard, which reached the tournament for a fourth straight season. The Crimson earned a spot this year after winning a one-game playoff against Yale to capture the Ivy League crown.

"Can't say enough about the effort that our kids put forth, to battle to get back in it," Harvard coach Tommy Amaker said.

Harvard had won its opening game the past two seasons against No. 3 seed New Mexico and fifth-seeded Cincinnati, but played from behind throughout in this one.

The Tar Heels dropped six of their last 10 regular season games, but came together in Greensboro during the ACC Tournament. They defeated top-seeded Virginia in the semifinals there before falling to Notre Dame in the final.

North Carolina rode the wave of momentum from its strong tournament showing into the first half Thursday and held a 52-36 advantage after Tokoto's steal led to a Paige layup with 15:23 remaining in the game.

Harvard made its move with a 12-4 run during the middle stages of the frame. Corbin Miller sunk a pair of free throws to cap the surge and cut the margin to 58-55 with 6:15 left.

Chambers' jumper coupled with two Steve Moundou-Missi bonus shots trimmed the deficit to 60-59, but Paige countered with a left wing 3 to put UNC back up by four with 3:23 on the clock.

Saunders' jumper on Harvard's next trip down the floor again made it a one- possession contest.

Earlier, UNC held an 8-7 edge before getting separation with a 13-0 run. Tokoto nailed a jumper to cap the surge and stake the Tar Heels to a 21-7 advantage.

Harvard made a surge to temporarily claw back, but the Tar Heels answered back and closed the first half strong.

Eleven straight from the Crimson whittled the gap to three. Chambers finished off the burst with a triple to make it 26-23 at the 3:42 mark.

UNC, however, netted 10 of the final 12 points prior to the break. Isaiah Hicks put in seven points during the swing, with a late three-point play in the period helping the Tar Heels head into the locker room with a 36-25 cushion.

Game Notes

The Tar Heels held a 36-22 points in the paint and 35-26 rebounding advantage ... Harvard hit all 11 of its foul shots in the second half and finished 18- of-20 overall ... UNC was 5-of-7 from beyond the arc ... Saunders' 26 points were the most by a Crimson player in an NCAA Tournament game.