The Tigers (5-2) had lost the past two in the series and had squandered a 12-point lead to trail 31-28 early in the second half. That's when McDaniels and Devin Booker got going for Clemson.
McDaniels had four foul shots and a three-point play while Booker added eight points in the game-breaking run. When Booker hit a pair of free throws with 9:08 to play, Clemson was on top 49-37.
South Carolina (5-3) closed to 51-47 on Bruce Ellington's basket. But Damarcus Harrison made a 3-pointer to restore Clemson's edge.
Booker ended with 13 points and eight rebounds. McDaniels had seven boards and five of Clemson's eight blocked shots.
Brenton Williams led South Carolina with 16 points.