Rutgers shot 50 percent (24-of-48) for the game and improved to 9-11 overall.
Scottie Reynolds, who was averaging 17.5 points per game to lead the Wildcats, struggled through one of his worst shooting performances. The sophomore made just 5 of 19 shots from the field, missed 7 of 8 3-point attempts and finished with 16 points.
With 3:45 remaining, Grant tried to shoot the Wildcats back into the game. The freshman scored 17 straight points, including five 3-pointers. His two free throws made it 71-64 with 1:40 remaining.
But the Scarlet Knights made their free throws down the stretch to keep the Wildcats at bay.
Rutgers, which won its first conference game in seven tries, used a 16-2 run to stun the Wildcats to begin the game.
The Wildcats went almost 12 minutes without a basket beginning early in the second half and never recovered.
It was the Scarlet Knights' first victory over a ranked opponent since a 65-56 victory over No. 22 Louisville on Jan. 18, 2006.
Rutgers entered the game last in shooting percentage in the Big East but made eight of its first 10 shots and never trailed in the first half.
The Scarlet Knights made 16 of 25 shots (64 percent) in the first 20 minutes, including 6-of-11 (55 percent) from beyond the arc. Coburn and Farmer scored 13 points during the 16-2 run to start the game. They made seven of their first eight shots.
Villanova struggled out of the gate and finished the half 11-of-28, which included six 3-pointers.
Farmer, who averages 10.4 points a game, scored 15 points in the first half and made his third 3-pointer as time expired to send the Scarlet Knights into halftime with a 40-32 lead.
Villanova was once again without its leading rebounder, 6-foot-10 sophomore center Casiem Drummond, who missed his eighth game while nursing a stress fracture in his right ankle.
