Smith-Rivera hit 10-of-12 from the field as part of Georgetown's 63-percent shooting performance.
The Hoyas held a three-point lead with 6 minutes to go in the first half, then outscored DePaul 15-4 the rest of the way to intermission.
Nate Lubick had 15 points for Georgetown (20-4, 10-3 Big East). It was the Hoya's eighth straight victory.
The Blue Demons (11-15, 2-11) have lost 10 out of 11. Brandon Young scored 16 points with seven rebounds for DePaul.