Amber Harris had 21 points and 10 rebounds and No. 6 Xavier shot a season-best 66 percent, handling Saint Louis 92-60 for its 12th straight victory on Wednesday night.
Ta'Shia Phillips added 20 points and seven rebounds for the Musketeers (22-2, 10-0 Atlantic 10), who've beaten half of their opponents during the winning streak by 20 or more points.
The four-time defending Atlantic 10 champions have won 26 consecutive regular-season conference games and easily topped their previous best shooting percentage of 55.7 percent in the opener against South Carolina.
Jacy Bradley had 13 points and reserve Ashley Hanley matched her career best with four 3-pointers and 12 points for Saint Louis (7-19, 1-10), which has lost six in a row by an average margin of 26 points and 12 of 13 overall.
The Billikens matched their season best with eight 3-pointers but faded after hitting their first five shots, three by Mallory Eggert, shooting 35.6 percent.
Xavier was shooting better than 70 percent before coach Kevin McGuff emptied the bench. Harris has 13 double doubles this season.
Saint Louis led 9-4 early but was 4 for 27 to end the first half while Xavier took a 46-22 lead. Harris had five points in an 11-0 run that put Xavier ahead 21-13 with just under 12 minutes left in the half.