"This was a nice win for us," SLU coach Rick Majerus said.
Saint Louis (23-11) will next play at Virginia Commonwealth (25-9) on Monday night. The teams will then play at Chaifetz Arena on Wednesday and, if needed, again on Friday.
SLU's 23 victories are the most since the 1994-95 team won 23 games.
The Billikens played some of their best basketball of the season at times against Princeton (22-9) on Wednesday, led by the standout sophomore tandem of point guard Kwamain Mitchell and power forward Willie Reed.
Mitchell scored 17 of his game-high 21 points in the first half and finished with five assists in a team-high 36 minutes. Reed registered his ninth double-double of the season with 20 points and 10 rebounds.
Freshman forward Cody Ellis and sophomore forward Brian Conklin added nine points and four rebounds apiece. The Billikens shot 54.5 percent from the field (24 of 44), which was their second-highest total of the season.
"I thought our defense was pretty good again," Majerus said. ‘We're hard to score against."
Saint Louis withstood an early barrage of 3-pointers and long jumpers by the hot-shooting Tigers in the opening minutes and led 38-29 at halftime after scoring the final seven points of the first half.
After the Billikens scored the first eight points of the second half, including 3-pointers from Ellis and sophomore guard Kyle Cassity, Saint Louis had pieced together a 15-0 run and was able to extend its lead to 17 points.
Princeton rallied in the second half, but wasn't able to threaten SLU's lead as the Billikens made nine of 14 free throws in the final two minutes.
"It's a good club, a really sound team," Majerus said of the Tigers. "They don't beat themselves. You have to beat them. We almost beat ourselves."