TALLAHASSEE, Fla. -- Clemson quarterback Deshaun Watson is a Heisman Trophy candidate and proved why by helping to maintain the No. 3 Tigers' perfect season.

Watson's 34-yard touchdown pass to Jordan Leggett with 2:06 left gave Clemson a wild 37-34 victory over No. 12 Florida State on Saturday that knocked the Seminoles out of ACC title contention and left coach Jimbo Fisher fuming over a controversial chop block penalty that thwarted a fourth-quarter drive.

Leggett cut up the sideline and dove into the end zone for the go-ahead score as Clemson won at Doak Campbell Stadium for the first time since 2006.

Clemson (8-0, 5-0 ACC), led by linebacker Kendall Joseph with seven tackles and a sack, held off the Seminoles (5-3, 2-3) on their final drive.

"I don't know how you could expect anything less from Clemson-Florida State," Tigers coach Dabo Swinney said. "What a game."

Clemson jumped out to a 14-0 lead and looked like it was going to win easy, but by the third quarter found itself trailing 28-20 after back-to-back long touchdown runs by Seminoles running back Dalvin Cook.

The Tigers, though, outscored the Seminoles 17-6 the rest of the way to remain perfect and in the hunt for one of the four College Football Playoff spots.

Watson finished 27 of 43 for 378 yards with two touchdowns and two interceptions.

Swinney called Watson "the best player in college football" after the game, despite the errors.

"He's not perfect. He's not a robot," Swinney said. "I don't know any player who is."

Watson credited his teammates -- specifically his defense -- for the win.

"Our defensive coordinator is excellent, and the defense was great (Saturday night), dialing up all kinds of different sorts of pressures," Watson said. "I just told the guys (when we fell behind), 'Let's be special. Let's be great. This is what champions do.'"

Florida State appeared to move into field goal range with 43 seconds to play and a chance tie the game, but consecutive false start penalties and back-to-back sacks of quarterback Deondre Francois ended their last-gasp effort.

The controversial penalty came with nine minutes left in the fourth quarter and the Seminoles ahead 28-26. Cook broke a long run that put the Seminoles in Tigers territory, but the play was called back because of what was ruled an illegal block by fullback Freddie Stevenson, who appeared to make a clean play in the open field.

Fisher, incensed on the sideline over the call, received a sideline warning and eventually a penalty, backing the Seminoles up to near their goal line rather than driving on the Clemson side of the field.

"That's a critical call. It was ridiculous. It was not a chop," an irate Fisher said during his post game interview. "(It was) cowardly, gutless and wrong. It was a huge call in the game. Bad, real bad (call). But this is not why we lost the game. It is just a shame that you could have changed and seen what happened if you called the game correctly."

Florida State was forced to punt and the Tigers got into range for kicker Greg Huegel, who booted a 46-yard go-ahead field goal that gave Clemson a 29-28 lead with 5:25 left.

Cook's 8-yard scamper into the end zone with 3:23 to play put Florida State back ahead, setting the stage for Watson's heroics.

The loss erased a masterful performance by Cook, a Heisman contender himself who rushed for 169 yards and a career-high four touchdowns. Cook posted his fifth straight 100-yard rushing game and became the seventh running back in history to eclipse 1,000 yards for three straight seasons.

Cook is 192 yards away from breaking the Seminoles' all-time rushing record held by Warrick Dunn since 1996.

But he was the first to admit, the penalties were a killer Saturday.

"You can't never get into a rhythm as a team ... with penalties like that. We have to clean those things up as a team, especially the offense," said Cook, who has 1,069 yards on the season and leads the FBS in yards from scrimmage.

Cook said he's trade that record for something else.

"What I really wanted to accomplish (this year) was a national championship," he said. "I'm not a guy of stats. I'm a guy of wins and losses. I'm a team guy."

Francois finished 17 of 35 for 286 yards with a touchdown and interception.

The Florida State defense was paced by defensive back Trey Marshall, who recorded a career-high 11 tackles but was tossed in the third quarter for targeting.

"I didn't think it was targeting. I still don't," Fisher said. "Whoever is in the booth is bad, too."

Seminoles defensive backs Marquez White and Tavarus McFadden -- the nation's leader with six picks -- each recorded interceptions.

Florida State's leading wideout was sophomore Nyqwan Murray, who recorded 96 yards on six catches and his first career touchdown.

Clemson running back Wayne Gallman -- in his first game back after suffering a concussion against N.C. State three weeks ago -- rushed for 82 yards and two scores. Leggett (five catches, 122 yards), Mike Williams (seven catches, 70 yards) and Hunter Renfrow (five receptions, 62 yards, TD) paced Tigers' receivers.

Jadar Johnson intercepted a pass for Clemson.

The Tigers didn't wait long to announce their presence at Doak Campbell Stadium, where they had only won once in the last 24 years.

Aided by a gutsy fourth-and-1 call by Swinney at midfield on the opening drive -- which Gallman converted -- the Tigers marched 68 yards in the opening 3:55 as Gallman punched it in from a yard out to open the scoring.

Clemson quickly made it 14-0 with 1:41 left in the first quarter when the Tigers converted on their second drive -- a 10-play, 80-yard march in just under four minutes. Watson recorded his first passing touchdown of the game, a 4-yard dart to Renfrow.

Florida State finally got on the board in the first half on its third possession, thanks to White's interception. Six plays and 60 yards later, Cook punched it in from 4 yards out to get the Seminoles their first points and close the gap to a 14-7 Clemson edge.

Clemson added three points late in the second quarter when Huegel drilled a 23-yarder to put the Tigers up 17-7, but the Seminoles answered with 23 seconds remaining in the half when Francois found Murray from 5 yards out for a touchdown.

NOTES: Florida State played the 800th game in program history ... This marked the sixth straight meeting in which both teams were ranked in the Top 25, and the fifth straight with at least one program in the top five. ... Clemson coach Dabo Swinney improved to 15-3 after an open date. ... Neither the Tigers nor Seminoles played last week. ... Florida State honored two former star players during Saturday's game -- receiver Monk Bonasorte and linebacker Derrick Brooks. Bonasorte was the honorary captain, and Brooks was recognized for being elected to the College Football Hall of Fame. ... Seminoles starting wideout Jesus Wilson (foot) did not play. ... Saturday's announced attendance was 78,025 -- the largest crowd for a Florida State home game this year.