BUFFALO, N.Y. -- Pete Campbell was out of his zone. He found it in the nick of time.
After missing all three of his shots in the first half Thursday, Campbell found his range midway through the second, hitting three 3-pointers to spark a 17-0 run and help Butler beat Old Dominion 57-46 in a first-round NCAA matchup between mid-majors.
The three baskets were the only ones of the game for Campbell, but the first came with the score tied at 32-all and the next two followed in a span of just 54 seconds.
"It's huge whenever he goes off for us," said Brandon Crone, who finished with 12 points. "It definitely gives you a lift, but he's done that all year, coming in and hitting big shot after big shot. You definitely feed off of that. Once he gets going, they start focusing on him and it opens up a lot. It's huge whenever he goes off for us."
It was anybody's game until then. Butler (28-6), trailing 32-29 after Valdas Vasylius hit a 3-pointer with 12:22 remaining, tied it with A.J. Graves' 3 from right wing, and then Campbell found his range.
"We just calmed down," said Graves, who led Butler with 18 points. "In the first half, we were rushing our shots. In the second half, we calmed down with the environment around us, got some open looks, and just knocked them down."
Campbell connected twice to break the 32-all tie. He nailed his first 3 from right wing at 10:28 and, after Brandon Johnson missed a 3 for Old Dominion, followed with a 3 from left wing for a 38-32 lead with 9:34 left.
"The first time it was in transition, and they kind of just lost me out on the wing," said Campbell, who was an impressive 62-for-109 in the previous 19 games (56.9 percent). The next two plays were called for me out of timeouts."
"When he hit another, we thought, 'Well, let's try again,'" Butler coach Todd Lickliter joked. "He's a terrific shooter, understands that's his job and probably gets anxious. I thought in the second half he settled down a little bit and we were able to find him."
Campbell made his third 3 from the left side, missed another, then watched Mike Green drain one from the top of the key and follow that with a driving layup to boost the lead to 46-32 with 6:19 left.
Old Dominion (24-9) had won 12 of 13 games and even posted an early season victory over eventual Big East champion Georgetown, a second seed in the NCAA Tournament. But Butler, ranked in the top 20 for 15 weeks, held Old Dominion scoreless for 7:24 during the decisive run.
"Doggone it. I see 12 lead changes, and with 12 minutes left in the game we had every opportunity in the world," ODU coach Blaine Taylor said. "But Butler's had a fabulous season. It seems like they've found a way many nights, many days, to get to the winners' circle."
On this day, the seniors struggled, going a combined 7-for-28. Dahi had 10 points, but the 6-foot-7 Vasylius, the team's leading scorer at nearly 16 points per game, finished with 10 points on 3-for-12 shooting. Williamson, who didn't score until he converted his own steal with a fast-break layup with 16:20 left in the game, finished with two points before fouling out in the final minute.
"You just miss some shots sometimes," Williamson said. "I hate that it was this game."
Butler, the fifth seed in the Midwest and tournament-tested with six appearances in 11 years, set a school record for victories in a season.
The Bulldogs will meet fourth-seeded Maryland in the second round Saturday. The Terps (25-8) beat 13th-seeded Davidson 82-70.
The Bulldogs have become one of the nation's model mid-major programs. They had equaled the team record set four years ago, when they pulled off two big upsets as a 12th seed to make it to the round of 16. And they were determined not to become a victim of a 12th seed.
Brandon Johnson led Old Dominion with 11 points and freshman Gerald Lee, a native of Finland, had 10 points and 11 rebounds, his first career double-double.
A 12th seed has beaten a No. 5 in each of the last six years. Butler did it in 2003 and this year had landed the highest seed in school history, prompting many experts to pick Old Dominion for an upset.
"Whenever we play for championships, we want to be successful," Lickliter said. "This team has competed. I know they had a lot of doubters."