Trailing 52-49, Slaughter made two free throws with 5:22 left. Neither team scored until Sara Hammond’s two foul shots put the Cardinals (17-4, 5-2 Big East) on top with 3:05 to go.
Hammond hit two more free throws and Bria Smith’s layup gave Louisville a five-point cushion with 1:45 remaining.
Two free throws by the Red Storm’s Shenneika Smith made it 57-54 with 42 seconds showing. She then blocked a Shoni Schmimmel jumper, but missed a 3-pointer with 9 seconds left. After an Aliyyah Handford steal, Nadirah McKenith missed a 3-point try at the buzzer.
The Cardinals hit 21 of 25 free throws compared to 7 of 15 for St. John’s.
Shenneika Smith scored 23 as the Red Storm (9-9, 3-3) dropped their third straight.