CLEMSON, S.C. (AP) Clemson had teetered on the edge of defeat most of the year, so when it finally occurred, the loss to Pittsburgh left the Tigers more puzzled than shocked.
The Tigers' perfectly planned structure, built on a foundation of last year's dominance, showed cracks and instability since the season began. Too many turnovers, too few experienced defenders and some debatable coaching calls caught up to seemingly unflappable Clemson (9-1, 6-1 Atlantic Coast Conference) in a 43-42 loss to Pittsburgh on Saturday when Chris Blewitt nailed a 48-yard field goal with six seconds left.
Clemson was among three of the top four College Football Playoff poll teams to lose undefeated seasons, sliding from No. 3 last week to No. 5 . And the first home loss since 2013 has left the Tigers questioning how quickly they'll rebound for a second consecutive national title run.
''We haven't experienced any losses like that, especially at home, not in a long time,'' said Deshaun Watson, whose ACC-record 580-yard passing game will be overshadowed by his three interceptions, two near the end zone. ''Just have to keep our heads up, realize not everybody's perfect.''
Clemson captured college football's attention last season with its dominant defense and unstoppable offense, led by Watson's knack for delivering the perfect pass. The Tigers rode that combo to a No. 1 ranking at 14-0, an ACC title and the national championship game, where Watson put on a dazzling show with 478 yards of offense and four touchdowns in a 45-40 loss to Alabama.
Talk instantly began of a super offense, perhaps the game's best ever, led by Watson and featuring proven playmakers like tailback Wayne Gallman and receivers Mike Williams and Artavis Scott.
From the start, though, things were not the same. Clemson opened with underwhelming six-point wins over Auburn and Troy, and fans, analysts and even Watson wondering what was wrong.
Clemson looked to gain momentum following a hard-fought, 42-36 win over then-No. 3 Louisville on Oct. 1 to start 4-0. The mistakes continued, though, and nearly cost the Tigers two weeks later against North Carolina State when kicker Kyle Bambard missed a potential game-winning, 33-yard field goal attempt at the end of regulation in a 24-17 overtime win .
In that game, Clemson coach Dabo Swinney went for a fourth-and-one in OT - a bold call because it worked - with C.J. Fuller leaping ahead to keep the drive alive before Watson's winning 10-yard TD toss to Scott.
That same, put-it-away attitude by Swinney cost the Tigers this time when Gallman was stopped on third- and fourth-and-one at the Pittsburgh 35 with a minute left. A punt into the end zone, at worst, would've left the Panthers 15 more yards to gain in the final 58 seconds.
Instead, quarterback Nathan Peterman moved Pitt 34 yards into range for Blewitt, who kicked it straight through.
''We had been making those kinds of plays this year,'' Swinney said of failed runs.
Clemson's mistakes are up from last year. Watson entered this year with 15 career interceptions and has 13 picks in 10 games this year. The Tigers have 21 turnovers this season after 27 in their 15 games a season ago.
Two of Watson's interceptions came with Clemson deep in Pitt territory driving for scores. The last one by linebacker Saleem Brightwell came in the fourth quarter with the Tigers up 42-34 and in the red zone.
Clemson's re-manned defense, which lost seven starters from last year, including six taken in the last NFL draft, was also gashed by the Panthers. The Tigers overachieved much of the year but allowed their most points and second most yards (464).
Watson said it's essential that Clemson regain its swagger and finish strong.
''At the end of the day, the attitude is still positive,'' he said.
Clemson's championship goals, especially with losses by previously undefeated No. 4 Michigan and No. 7 Washington this weekend, remain intact, Watson said. The Tigers would clinch the ACC Atlantic by beating Wake Forest on Saturday. They close the season at home against rival South Carolina. Win the ACC title game and the Tigers, with all their flaws, likely head back to the playoffs.
''This team has the heart of a champion, and that will be revealed,'' Swinney said. ''I believe that adversity builds character and reveals it. I know what this team is made of, and we'll fight back, respond and move on.''
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