Rotnei Clarke scored 17 points to lead Butler to a 68-56 win over Bucknell in the second round of the NCAA Tournament.
Andrew Smith scored 14 points and grabbed 16 rebounds for the Bulldogs (27-8), who failed to reach the NCAA Tournament last spring after playing in the national championship game in 2010 and 2011.
"The similarity is they're Butler," said Bulldogs coach Brad Stevens. "They have some mettle. They have some intestinal fortitude built up over time. The difference is just the people. We have to play a little bit differently on both sides of floor because of it."
Roosevelt Jones also scored 14 points and Alex Barlow tallied 10 points for the Bulldogs, who are seeded sixth in the East Region and will face Marquette in the third round on Saturday.
Joe Willman had 20 points and six rebounds for Bucknell (28-6), which won the Patriot League title and was making its second NCAA Tournament appearance in three years. Patriot League Player of the Year Mike Muscala had nine points and 10 rebounds in defeat. He made just 4-of-17 shots.
"I just think they've played in so many big games, they're not the type of team that's going to get rattled," said Bison coach Dave Paulsen
Down 31-26 with 13:15 remaining in regulation, Bucknell went on an 11-0 surge to take a 37-31 lead with just over 10 minutes to play.
The Bulldogs responded with an 8-0 spurt, capped with triples by Smith and Clarke to regain the lead, before Ryan Frazier converted a three-point play to put the Bison back on top.
Smith, though, made a jumper and Barlow drove for a layup to give Butler a 43-40 edge with 7:28 to go.
After Willman made a jumper, the Bulldogs scored the next 10 points and had a 53-42 advantage with 2:38 remaining. The Bison got only as close as eight from there.
The Bulldogs sealed it by making 18-of-20 from the foul line in the final 4:43 and finished 25-of-28 from the stripe overall.
Butler had a 21-14 lead at halftime.
Butler's Kameron Woods had eight rebounds off the bench ... Willman shot 10- of-16 from the field ... Butler and Bucknell were a combined 0-for-11 from beyond the arc in the first half ... The Bulldogs finished 3-of-17 from beyond the arc ... Patriot League teams are 3-22 all-time in the NCAA Tournament.