Freshman Walker Kessler cranked out a season-high 20 points and North Carolina stormed back from a miserable first-half stretch to defeat No. 11 Florida State 78-70 on Saturday in Chapel Hill, N.C.Kerwin Walton added 13 points and RJ Davis and Caleb Love both posted 12 points as North Carolina’s top four scorers were freshmen. Kessler, who shot 9-for-10 from the field, had a team-best eight rebounds.The Tar Heels (15-8, 9-5 ACC) overcame a 16-point hole despite 21 turnovers. They shot 10-for-10 on free throws in the final 2 1/2 minutes as coach Roy Williams picked up his 900th career victory.Williams became just the fourth coach in Division I men’s history with 900 wins along with Duke’s Mike Krzyzewski, Jim Boeheim and Bob Knight. He also became the fasted in D-I history to reach that milestone in 1,161 career games.Florida State (14-4, 10-3), which had a four-game winning streak halted, was trying to put a firmer grip on first place in the ACC.RaiQuan Gray’s 17 points, Scottie Barnes’ 12 points and Anthony Polite’s 10 points paced the Seminoles.Davis hit a 3-pointer to send the Tar Heels to a 55-50 advantage. Kessler made the next two North Carolina baskets, the latter with the center out front on a fast break as the margin ballooned to 59-52 with less than nine minutes to play.The Seminoles had a chance to cut the deficit to one, but Barnes botched a breakaway opportunity as Love was credited with a blocked shot just before the four-minute mark. The Tar Heels converted with Armando Bacot’s dunk at the other end. Florida State never got closer than four points the rest of the way.