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 straight 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. Seven-footer Sergio Olmos excited the crowd on the opposite end, blocking shots on consecutive possessions.
Christmas then showed off his inside game, spinning and driving to the basket for a tough layup to make it 65-50.
Xavier made only one shot over a 6-minute span before Drew Lavender scored to end the slump.
Temple's last win over a Top 25 team came against No. 6 George Washington in the quarterfinals of the A-10 tournament in 2006. A small-but-enthusiastic crowd ran onto the court to celebrate this victory.
