Notre Dame set a school record for most consecutive victories in the conference with its ninth straight triumph.
The Irish led by just two points at halftime before breaking open the contest over the final 20 minutes. Grant made 8-of-11 shots from the field and Notre Dame hit 61 percent of its field goal attempts.
Scott Martin added 15 points for the Irish (20-9, 12-3 Big East). Jack Cooley and Eric Atkins scored 13 each.
West Virginia (17-11, 7-8), which has lost six out of eight, was led by Kevin Jones with 15 points.
Notre Dame was good on 9-of-16 attempts from beyond the 3-point arc -- four of them by Grant.