Semaj Christon contributed 15 points to help the Musketeers (18-8, 8-5) retain at least a share of third place in the Big East Conference.
It was the most complete performance of the season for Davis who also had two steals, just one turnover, and went four of five from 3-point range.
Freshman Billy Garrett Jr. scored 16 points and Forrest Robinson added 14 points off the bench for DePaul (10-17, 2-12), which lost for the ninth straight time.
Brandon Young added 12 points for the Blue Demons who again played short-handed. For the third straight game DePaul played without star forward Cleveland Melvin who left the program for unspecified reasons after averaging 16.7 points in seven contests.
Melvin scored 25 points on Jan. 20 in an 84-74 loss to Xavier in Chicago, his last game prior to serving a four-game suspension for violating team rules.
Sophomore guard Durrell McDonald made just his third start of the season.
Although Xavier was a heavy favorite, head coach Chris Mack wanted a consistent defensive effort from his team, which it hadn't done often this season.
The Musketeers made things tough for the Blue Demons early, holding them to 1-of-11 shooting. DePaul went scoreless until Young's layup with 15:37 left.
The Blue Demons shot 30 percent in the first half, as compared to 60 percent for Xavier. But, DePaul also committed 10 turnovers resulting in 13 of XU's points.
Myles Davis' 3-pointer put Xavier ahead 12-2.
Christon, who scored 27 points in the first meeting, scored 10 points in the first hal, helping Xavier build a 12-point halftime lead.
Despite being short-handed, the Blue Demons didn't go quietly.
Consecutive 3's by Robinson helped them get within 10 points late in the first half. But, Xavier didn't relent.
Matt Stainbrook's layup off a lob from Christon, highlighting a 14-0 Musketeers' run to begin the second half. Davis' transition layup off a feed from Christon capped the run and made the score 53-27.