Starks hit 8-of-12 shots, including three from 3-point range, to go along with Porter's 19 points and 14 rebounds for the Hoyas (17-4, 7-3 Big East), who won their fifth consecutive game.
The loss extended Rutgers' (12-10, 3-8) losing streak to six games.
Eli Carter, with 23 points, was the only Rutgers player in double figures.
The score was tied 33-33 at halftime. Rutgers trailed 62-61 with 1:28 to play in the second half, but only scored one field goal the rest of the way while Georgetown's Porter racked up seven points.