Clarke ranked third in the A-10 in scoring and took a hard foul on a break-away lay-up attempt and crashed into the basket support with just over eight minutes remaining in the first half. He remained down until medical personnel helped him off the floor on a stretcher. He was taken to a local hospital, where examination revealed no fracture.
"Rotnei's going to be fine," Butler associate head coach Matthew Graves said in a release. "Coach (Brad) Stevens is at the hospital with him and (Rotnei) is being discharged now, and his first words were 'I want to ride the bus home with the team'."
In Clarke's absence the Bulldogs pulled together with a strong team performance to notch their 11th consecutive win. Ten players saw at least nine minutes of action, and each cracked the scoring column.
Sophomore Roosevelt Jones led the way with 16 points, while senior Andrew Smith chipped in with 13 points, four rebounds, as many assists and a blocked shot. Sophomore Khyle Marshall finished with 12 points.
"Our guys did a great job of bringing up the energy," Smith said. "Our bench came up huge for us; everyone stepped up and played really well. We finished great around the rim, and that was big for us."
Jones, in particular, was a menace inside. He hit four of eight shots off a variety of inside drives, and made his way to the free throw line 12 times, where he converted a career-best eight charity tosses.
The 6-foot-4 forward led the Bulldogs with seven rebounds, and he shared the team lead in assists with four.
The Bulldogs, who trailed early in the game, broke a 16-16 tie with a 7-0 scoring run. Marshall started the run with a dunk, and Clarke followed with the steal that ended with his injury. Marshall hit one of two free throws in Clarke's absence, and the Bulldogs retained the ball on the flagrant foul.
Jones completed the possession with a lay-up and Smith added a jumper a minute later to give Butler a 23-16 advantage. The Bulldogs remained in front for the rest of the game.
"We had a lot of guys come in and play different roles and do things they're not normally asked to do," Graves said. "We were really pleased with how well (the team) stayed together and stayed the course. Of all the wins we've had in Butler history, this ranks right up there with the best, because you see one of your top players go down in a tough environment on the road in a conference game. Our guys really hung tough and we're really proud of them."
Butler led 35-27 at halftime and stretched the lead to as many as 14 points in the second half.
Dayton (10-6, 0-2 A-10) mounted a late charge and trimmed the margin to 75-71 with under a minute remaining, but the Bulldogs held on with two free throws each by freshman Kellen Dunham and sophomore Alex Barlow in the final 0:31.
Dyshawn Pierre and Vee Sanford led four Dayton players in double-figures with 14 points apiece.
The Bulldogs will play their first Atlantic 10 Conference home game Wednesday at 7 p.m. against Richmond.