It was the redshirt junior's first trip to the endzone this season.
Grimble caught two passes for 39 yards, including the 30 yard touchdown, in the Trojans 17-14 win over the Aggies.
"I love catching the ball," Grimble said. "I can make a lot of plays in the passing game."
Grimble says before the Trojans travel to Arizona State next week they need to find a better rhythm with starting quarterback Cody Kessler. "A lot of us have been playing here for a few years," he explained, "but this is our first time playing with Cody. He's doing a good job and we're going to get better."
Through USC's first four games Grimble has caught four passes for 88 yards.