John Bazemore, Associated Press
Tennessee's Tyler Smith (1) and JaJaun Smith (2) celebrate after defeating Butler in overtime.

BIRMINGHAM, Ala. — The Tennessee Volunteers scrapped, pounded and grabbed.

They also survived. No coincidence in that.

The second-seeded Vols mostly ditched the glamorous 3-pointer and got physical in Sunday's second round, moving on with a 76-71 overtime victory over Butler.

Tennessee (31-4) got a little assist from Lady Vols coach Pat Summitt, who called her men's counterpart a few hours before the game.

"She said, 'Just tell those guys to rebound the basketball,"' Bruce Pearl said of the colleague, whose seven national titles make her something of an expert.

JaJuan Smith hit four straight free throws in the final 13.6 seconds of overtime and the Vols barely won a game they at times threatened to turn into an East Regional rout.

The earliest game to feature two 30-win teams definitely lived up to the distinction.

The Vols, who struggled at times against American in the first round, will play Louisville on Thursday in Charlotte, N.C.

Tennessee scored 38 points in the paint, had five players with multiple fouls by halftime and made only two 3s in the final 40 minutes against the Bulldogs (30-4).

"Fatigue was a factor for them at some point, because of the way we guarded them," Pearl said. "We really played great defense tonight and did what we needed to do on the boards."

The approach paid off at the end.

The Vols scored six straight points inside after the Bulldogs took their first lead in the final 2 minutes of OT, including benched guard Ramar Smith's basket with 27 seconds left to make it 72-68.

Butler still wouldn't go away. Pete Campbell followed a missed shot to make it 72-70 with 16 seconds left. JaJaun Smith then made both free throws.

Julian Betko rebounded a missed 3-pointer by A.J. Graves and was fouled with 4.9 seconds left for Butler. He made 1-of-2 from the line, and JaJuan Smith grabbed the rebound before icing the game with foul shots at the other end.

The Bulldogs, who got a low seed considering their No. 11 national ranking, didn't have their minds changed. Coach Brad Stevens remains convinced his team is "Final Four-caliber," and his players agree.

"Why wouldn't we? We play our style of basketball," said Mike Green, who had 15 points, seven rebounds and five assists before fouling out late in overtime. "It's been very effective."

So has Tennessee's more fast-and-loose style.

JaJuan Smith sported the motivating message "No. 1 seed" on his sneakers for a second straight game for a Vols team that felt they were worthy. Tennessee survived the tournament's opening weekend for the second straight year and avoided another 2-seed flop. The Vols had fallen in the second round as a No. 2 seed in 2006, the only other time they were seeded as high.

Wayne Chism led foul-plagued Tennessee with 16 points, while Tyler Smith added 15 and eight rebounds and JaJuan Smith had 11.

The Vols led by 13 in the first half and 10 early in the second, but Butler kept coming back.

The Bulldogs, who couldn't catch up to Tennessee for the first 37-plus minutes, took their first lead on Graves' short jumper in the paint to make it 68-66 with 1:46 left in overtime. Ramar Smith and Chism both scored inside to retake the lead inside the final minute.

Tyler Smith blocked Graves from behind and Chism won the scramble for the loose ball and called timeout with 33 seconds left. Smith was thankful the referees didn't call goaltending.

"I was so happy they gave it to me," he said. "I don't know if I caught it on the way up or the way down."

Ramar Smith then scored, coming up with a big play after losing his starting job to J.P. Prince, an Arizona transfer who made his first start for Tennessee.

NORTH CAROLINA 108, ARKANSAS 77: At Raleigh, N.C., North Carolina put on a show for its home-state fans in its first two NCAA tournament games. Now the overall No. 1 seed is off and running to the round of 16, where another comfortable setting awaits.

Wayne Ellington scored 20 points and the Tar Heels raced to a double-digit lead in the first 5 minutes of a 108-77 second-round win over Arkansas on Sunday, sending North Carolina to Charlotte for the East Regional semifinals.

Ty Lawson had 19 points and seven assists for the Tar Heels (34-2), who followed their first-round rout of Mount St. Mary's with another impressive offensive display. North Carolina will face fourth-seeded Washington State on Thursday night in the same arena where it won the Atlantic Coast Conference tournament last weekend.

The Tar Heels scored the first nine points, led 51-26 at halftime and shot 68 percent for the game. They became the first team to score 100 points in their first two NCAA games since Loyola Marymount did it against New Mexico State and Michigan in 1990.

LOUISVILLE 78, OKLAHOMA 48: At Birmingham, Ala., Rick Pitino and Louisville pressed on.

Earl Clark scored 14 points and the Cardinals played to near perfection on both ends, romping past Oklahoma 78-48 Sunday in the second round of the East Regional.

Louisville harassed freshman star Blake Griffin with double teams down low, trapped the Sooners and ran every chance it got. The Cardinals neatly zipped passes in the paint — that bit of insider trading paid off with easy baskets all game.

Even plays Pitino didn't draw up worked out. The coach walked off with a wry smile after little-used Will Scott hit a 35-footer at the halftime buzzer for a 44-22 lead.

Starting five players born outside Kentucky, the third-seeded Cardinals (26-8) reached the round of 16 for the first time since 2005. They will take on Tennessee, which beat Butler 76-71 in overtime, on Thursday night in Charlotte, N.C.