The Wolfpack dominated the boards and got plenty of second-chance baskets to stay in control of this one, earning a third straight win overall heading into this weekend's trip to rival North Carolina.
Michael Snaer scored 20 to lead the Seminoles, who have lost three of four since beating Georgia Tech on his last-second basket two weeks ago.
Warren, a 6-foot-8 forward, earned just his fifth start. He finished 12-for-15 from the field and hit two 3-pointers in 31 minutes.
While Warren turned in the best game of his young career, Leslie added 10 rebounds to help the Wolfpack take a 45-21 rebounding advantage. That included a dominating 21-6 performance on the offensive glass, which helped N.C. State manage 29 second-chance points compared to just six for Florida State.
Scott Wood added 13 points for N.C. State, which stayed in the chase for one of the league's four first-day byes in next month's ACC tournament in Greensboro.
The Wolfpack led 40-30 at halftime, then gradually increased the margin through the first eight minutes to 58-41 on a pair of free throws from Leslie with 11:59 left. The Seminoles hung around but never got the lead to single digits, getting as close as 10 with about 7 minutes left before Warren and Wood knocked down 3s to push the lead back up to 16 with 5 1/2 minutes left.
Warren's three-point play with about 90 seconds left helped N.C. State blow the game open late and had Wolfpack fans chanting his name as he finished with 20 second-half points.
It was N.C. State's first win against Florida State since beating the Seminoles in the quarterfinals of the 2010 ACC tournament.
Florida State has now been outrebounded in 12 of 14 games.