Grant provided 13 points while Knight added 12 to go with seven rebounds as the Fighting Irish (22-6, 10-5 Big East) won a second consecutive game.
Jack Cooley (11 points, eight boards) and Eric Atkins (11, six assists) also made big contributions in the win.
The Bearcats (19-9, 7-8) were paced by JaQuon Parker's 12 points in dropping their third straight contest.
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