Dwayne Bacon scored 21 points and Malik Beasley 16 as Florida State took advantage of a sloppy performance by Clemson to beat the Tigers 76-65 on Saturday.
Despite its struggles, Clemson led 41-40 with just over 12 minutes to play, but the Seminoles would outscore the Tigers 36-24 from that point to clinch the win.
Jaron Blossomgame scored 22 points to lead Clemson, including 9 of 9 from the free-throw line, but didn't get much help as no other Tiger had more than 10.
Clemson shot just 33.3% from the field and turned the ball over 18 times, including five apiece by Blossomgame and Jordan Roper.
Clemson's post players, Landry Nnoko and Sidy Djitte, were ineffective and spent long stretches on the bench due to foul trouble.
Florida State dominated fast break points in the game, and Clemson simply allowed too many easy baskets to win a game in which it played so poorly on offense.
The Tigers travel to Winston-Salem to face Wake Forest on Tuesday night.