Billy Garrett Jr. made 13 of 13 free throws and finished with a season-high 20 points for DePaul (10-9, 4-2 Big East), which already has its most conference wins since the 2007-08 season. Aaron Simpson added a career-high 13 points.
Rysheed Jordan made a layup for St. John's, but couldn't convert the three-point play. After a turnover by the Blue Demons, Jordan made two free throws to tie it at 67 with 42 seconds remaining.
Henry and Durrell McDonald hit a pair of free throws apiece from there to seal it for DePaul.
Jordan, whose two free throws with 8 seconds left in regulation forced overtime, finished with 17 points, four assists and four steals for St. John's (12-5, 1-4).