Florida State’s offensive players were brooding over their worst half in nearly two years when senior receiver Rashad Greene decided it was time to speak up.

“Rashad is not a man of many words,” fill-in quarterback Sean Maguire said Saturday night. “He’s usually a leader by example. But he just stood up, called everyone out, told everyone what the deal was and how everyone has to start waking up because this is the season right here.

“I think everyone just turned on that switch in the second half.”

That included Maguire, the third-year sophomore who was thrown into the unenviable position of attempting to maintain Florida State’s No. 1 ranking, extend its 18-game winning and not mess up its chance to repeat as national champions. And he had to do it against No. 22 Clemson, the second-most-talented team in the ACC.

Maguire, starting in place of suspended star Jameis Winston, got it done with the help of a defense that came up with its biggest turnover and biggest stop in recent memory.

The result was a season-saving, 23-17 overtime victory before a raucous Doak Campbell Stadium crowd of 82,316 that put Florida State (3-0, 1-0 ACC) in prime position to return to its third consecutive ACC title game, thus keeping alive its national title hopes.

The Seminoles also will keep their spot atop the polls.

“We deserve to be No. 1,” said tight end Nick O’Leary of North Palm Beach.

Maguire was making the first collegiate start after Winston, last season’s Heisman Trophy winner, was suspended for shouting an obscene phrase Tuesday on campus.

Winston initially looked like he expected to play. During warmups, he was in full uniform. Coach Jimbo Fisher, looking none too pleased, sent Winston to the locker room. He changed into black sweatpants and game jersey (no pads).

Maguire finished 21-of-39 for 305 yards, one touchdown and two interceptions. He was sacked five times.

Fisher announced after the game that Winston will start Saturday at N.C. State (3:30 p.m., ABC/ESPN2).

Winston initially was suspended for a half, but that was extended to a full game after he reportedly was not fully honest in describing what happened.

“When your players misstep. … they understand there’s consequences,” Fisher said. “I don’t condone any of the comments Jameis made earlier this week or how or where he chose to make them. We felt like the one game made the most sense and I chose to keep that process internal.

“Now he’s served that punishment and he‘s ready to move forward.”

The game officially was decided when Karlos Williams ran 12 yards around the left end on the Seminoles’ second play of the overtime, giving FSU its first OT win since 2003.

But it really tilted FSU’s way when linebacker Reggie Northrup and end Chris Casher stopped freshman running back Adam Choice on fourth-and 1-from the 14 in Clemson’s first overtime possession.

Clemson coach Dabo Swinney did not trust his kicker, Ammon Lakip, who had missed field-goal attempts from 23 and 40 yards.

Fisher, however, knew he had the most reliable kicker in the country in Roberto Aguayo, who hit a 50-yarder in the first quarter.

In overtime, Fisher kept the ball on the ground despite the Seminoles’ stunning lack of success running Saturday night. FSU had -12 yards rushing entering the overtime, including a loss of 49 yards on the five sacks of Maguire.

But Williams carried twice for 25 yards in the Seminoles’ only offensive plays in overtime.

“We’re not perfect — we’re nowhere close,” Fisher said. “I’m anxious to see where this team can go. It’s got to get better.”

Maguire looked every bit like a player making his first start on a national stage, completing just 6-of-17 passes in the first half while FSU managed just 84 yards, including 4 yards on 13 plays in the second quarter.

FSU, fortunate to trail just 10-3 at the half, was held without a touchdown in the first half for the first time in 18 games or since Nov. 24, 2012, against Florida. That also was FSU’s last defeat.

“It was tough, that second quarter,” Maguire said. “We made a lot of mistakes, myself included.”

A second-half opening drive in which Maguire completed all but one of his seven passes and was capped by Mario Pender’s 1-yard run to tie the score at 10.

Suddenly, Florida State was alive with Winston watching from the sideline in jersey and baseball cap.

Greene, who had one catch for 4 yards in the first half, finished with nine for 135, including a 74-yard touchdown with 6:04 remaining that tied the score at 17.

O’Leary, Maguire’s roommate on the road, had a career-high six catches for 78 yards.

Maguire said the biggest piece of advice he got from Winston was, “When in doubt find 80 (Greene) or 35 (O’Leary). It worked out pretty well.”

But it would not have been possible if the defense had not bailed out Maguire after his biggest mistake of the game nearly cost FSU the win.

Clemson (1-2) was position to win after Maguire’s second interception gave the Tigers the ball at the Seminoles’ 26-yard line with 2:14 to play. But two plays later, defensive tackle Eddie Goldman stripped Clemson running back C.J. Davidson of the ball and defensive back Nate Andrews recovered at the FSU 14 with 1:36 to play.

Fearing another turnover and knowing he had Aguayo — a huge weapon in overtime — Fisher played for the extra session.

“My being aggressive there would have been stupid and could have taken the game away from our players,” he said.

Instead, they got the overtime victory to save their season.