Glennon amassed 218 of his 259 passing yards after halftime, finishing the game 30-of-55. Two of his scoring strikes came in the fourth quarter, including his 2-yard toss to Underwood with 16 seconds left.
The Wolfpack (4-2, 1-1 ACC) shook off a 16-0 halftime deficit with the help of Quintin Payton, who caught six passes for 79 yards, and Shadrach Thornton, who chipped in with 48 yards and a touchdown on four catches.
Chris Thompson picked up 141 yards on 25 carries for Florida State (5-1, 2-1), which also lost in Raleigh in 2010.
The Seminoles' E.J. Manuel completed 17-of-29 passes for 218 yards and a touchdown, but also was stung by a second-half interception.