The defending national champion Seminoles have won 28 games in a row, and completed consecutive undefeated regular seasons for the first time in school history. Florida State is the 16th team to accomplish the feat since 1950.
"Survive and advance," said Florida State Coach Jimbo Fisher. "That's what we did."
Winston threw a career-high four interceptions, including three in the first quarter. He finished 12 for 24 for 125 yards and two touchdowns. Tight end Nick O'Leary had two second-quarter touchdown catches to give Florida State a 21-9 lead.
The Gators (6-5) jumped out to a 9-0 lead, but the offense struggled. Treon Harris threw for 169 yards with a touchdown and two interceptions. Florida's Austin Hardin missed two second-half field-goal attempts that would have given the Gators the lead. Both field-goal attempts came after Florida State miscues.
Winston threw his fourth interception with 2:36 left in the third quarter when Brian Poole tipped the ball to himself on a throw intended for Travis Rudolph. Hardin missed the 52-yarder to the right five plays later.
Fisher called an odd fake punt that had defensive end Mario Edwards Jr. being stopped short on a rush to give Florida the ball with 11:48 left in the fourth quarter. Hardin missed a 42-yarder five plays later.
The Seminoles were held to a season-low 306 offensive yards and a season-low 125 passing yards. Winston's 125 passing yards was a career low.
Muschamp walked off the field for the final time as Florida coach arm in arm with his wife.
"We had our opportunities to get it done and we didn't get it done," Muschamp said. "It falls on my shoulders and that's why they're looking for a new coach. I'm just a guy that did it the right way. I'll hold my head up. We just didn't win enough games."