The Minuteman (12-4, 1-1 Atlantic 10) finished with 13 3-pointers and their speed in the open court to beat Dayton's defense.
Brian Roberts had 21 points for the Flyers (14-2, 2-1), who finished 4-for-25 from 3-point range as the Minutemen collapsed to helped inside.
Massachusetts had six blocked shots.
TEMPLE 78, NO. 20 XAVIER 59
In Philadelphia, Dionte Christ-mas scored 19 of his 23 points in the second half and Mark Tyndale added 22 to lead Temple.
The Owls (7-8, 1-1 Atlantic 10) beat a ranked opponent for the first time in two years to earn their biggest win since Fran Dunphy replaced Hall of Fame coach John Chaney last season.
Derrick Brown had 14 points for the Musketeers (14-4, 2-1), who had won six in a row by an average margin of 25.3 points since losing to then-No. 12 Tennessee on Dec. 22.
But Temple came ready to play from the start.
Luis Guzman scored all 13 of his points in the first half to tie his career-best. Sparked by Guzman's performance, Temple played one of its best halves using a 12-2 run to take a 27-21 lead.
Xavier answered with six consecutive points, including a thunderous dunk by Brown off an alley-oop pass from Stanley Burrell. Brown followed with two free throws to tie it, but Temple took a 30-27 halftime lead.
Christmas, Temple's leading scorer with a 20.5 average coming in, had just two field goals in the first half. He found his scoring touch after the break, getting 15 of the team's next 20 points.
Christmas hit two difficult 3-pointers a minute apart to give Temple a 47-43 lead. After a three-point play by Jason Love, Christmas nailed his fourth 3 and the Owls broke it open.
Ryan Brooks and Chris Clark finished off a 10-0 run with consecutive 3-pointers, extending the lead to 60-47 with 9:02 left.