Sharaud Curry added 12 points and Jonathan Kale 11 for Providence (9-8, 2-4 Big East), which won its second straight while handing Rutgers (12-7, 2-4) its third straight loss and fourth in five games.
McGrath shot 8-for-11 and Hill was 8-for-9 as Providence shot 60 percent.
Quincy Douby had 18 for Rutgers, tying the second-lowest total of the year for the Big East's leading scorer. Douby shot just 5-for-20 as Rutgers was 34.4 percent as a team.
Rutgers went without a field goal over the final 6:37 of the first half, as Providence took a 44-26 halftime lead.
Leading 33-23, the Friars ran off 11 straight, with Curry scoring seven points on consecutive possessions. He hit a 3-pointer, then came back to convert a four-point play. The run was completed when Douby blocked a layup attempt by Curry, only to have the ball go back to Hill for a slam.
The Knights climbed back after intermission, closing within 47-39 when a technical on the Providence bench led to two Douby foul shots and a Byron Joynes putback. The Friars responded with a 17-5 run, with Hill scoring six straight Providence points in the midst of the run.
J.R.Inman is stopped by Herbert Hill