Sibert had four 3-pointers as did Scoochie Smith, who finished with 14 points. Dyshawn Pierre added 15 points and Darrell Davis 11 for Dayton (12-2, 2-0 Atlantic-10), which shot 55.8 percent, including 14 of 24 from behind the arc (58.3).
Marcus Posley led St. Bonaventure (8-5, 1-1) with 17 points. Dion Wright added 13 and Andell Cumberbatch 10 for the Bonnies, who shot 41.7 percent. Youssou Ndoye had nine rebounds, ending his streak of double-figure boards at 10 straight games, tied for the nation's longest streak this season.
Dayton led by eight at halftime and went by double figures for good on a basket by Sibert with 12 minutes left. Three-pointers by Sibert and Smith put the Flyers up by 20 with 1:28 left.