Semaj Christon led all scorers with 20 points for Xavier, while Matt Stainbrook finished with 17 points and Justin Martinalso reach double figures with 13 as the Musketeers (12-3, 2-0 Big East) extended their winning streak to seven games and improved to 10-0 at home before a capacity crowd of 10,250.
Xavier's only losses were at the Battle 4 Atlantis tournament in the Bahamas.
Khyle Marshall led three Bulldogs in double figures with 14 points. Kellen Dunham scored 11 points and Elijah Brownadded 10 for Butler (10-4, 0-2), which has lost two straight games after a five-game winning streak. Both losses have been in the Big East. The Bulldogs lost, 73-70, to No. 11 Villanova on New Year's Eve.
Both teams are in their first season in the Big East.
The Bulldogs committed 15 turnovers, helping Xavier build a 14-4 advantage in points off of turnovers.
After 11 ties and five lead changes, the Musketeers took the lead for good, 66-64, on a Dee Davis layup with 5:56 to play in the game. Xavier pulled away from there and widened the final margin with some clutch free throws in the final 30 seconds.
After Erik Frommconnected on a jump hook to give Butler its largest lead, 44-37, 14 seconds into the second half, Davis scored five points during 9-0 Xavier run that left the Musketeers leading, 46-44, with 17:37 left in the half.
The Bulldogs made seven of their first eight shots from the field and shot 60.9 percent (14-of-23) from the field while building a 42-37 halftime lead. Marshall scored 11 points to lead Butler. Christon, who was averaging 14.4 points per game, scored 16 before halftime to help Xavier stay close.