An ACC showdown has an unlikely star, an SEC showdown has an enticing one-on-one matchup and East Carolina goes for two straight upsets.
Here are some things to know about the fourth weekend of the college football season:
WINSTON'S STAND-IN: Introducing Sean Maguire, starting quarterback for the No. 1 team in the country. As you might have heard Jameis Winston earned himself a full-game benching for some less-than-ideal behavior at Florida State this week. Enter Maguire, starting what might be the Seminoles' most significant game of the season against ACC Atlantic Division rival No. 22 Clemson. A loss could cost Florida State a chance to win the Atlantic Coast Conference title.
So who is Maguire? Well, he's not a big-time recruit. He ran the run-first, wing-T offense at Seton Hall Prep in New Jersey.
Coach Jimbo Fisher, however, has always been enamored with Maguire's strong arm and said he won't change the offense at all. Maguire has thrown 26 passes in college career. He was 3 of 5 for 28 yards after entering the Citadel game in the third quarter with a 34-0 lead two weeks ago. He played in nine games in 2013 and threw for 116 yards with two touchdowns and two interceptions.
His job is to not screw up and maybe make a few plays. And he's pumped for the chance.
''It's going to be pretty awesome, I'd like to imagine,'' Maguire said. ''I've pictured this since I started playing little league ball. ... I don't know how much better it gets than this.''
COOPER vs. HARGREAVES: The game between Florida and No. 3 Alabama features what could end up ranking among the top 1-on-1 matchups of the entire season, with Florida cornerback Vernon Hargreaves covering Alabama receiver Amari Cooper.
Cooper, a junior, leads all Football Bowl Subdivision players with 33 catches and ranks third nationally with 454 yards receiving. He's a future first-round pick. Hargreaves was a first-team all-SEC selection and a third-team AP All-America pick as a freshman last season. Another future first-rounder.
''Coop, he's a great player,'' Hargreaves said. ''Me and him, we talk a little bit. We knew this was coming. He's excited. I'm excited. We both know the magnitude of the game. It's going to be a great matchup on Saturday.''
ECU vs. ACC: East Carolina, a member of the American Athletic Conference, will try to continue its recent mastery of Atlantic Coast Conference teams when it hosts North Carolina.
The Pirates are coming off a 28-21 upset of Virginia Tech, which was ranked 17th at the time. East Carolina has won its last three games against ACC teams, a streak that includes a 55-31 victory at North Carolina last season. A home game with an in-state foe after an upset of a ranked team has created plenty of excitement around East Carolina's campus.
''The vibe is crazy right now,'' East Carolina linebacker Brandon Williams said.
GOING FOR 4-0: Two Atlantic Coast Conference teams are trying to reach 4-0 for the first time in a long time.
Duke takes its perfect record into a home game against Tulane (1-2). The Blue Devils are a heavy favorite to reach 4-0 for the first time since 1994, when they set a school record by winning their first seven games. There have been only three other times when Duke has started the season at least 4-0.
Pittsburgh goes for 4-0 at home against Iowa (2-1), which is coming off a tough loss to rival Iowa State. The Panthers haven't been 4-0 since 2000.
HOME RUN HOOSIER: Indiana, coming off a bad loss to Bowling Green, goes to No. 18 Missouri as a big underdog.
Tevin Coleman gives the Hoosiers at least a shot to pull the upset. The leading rusher in the country, Coleman is averaging 218 yards per game and 9.3 yards per carry.
AP College Football Writer Ralph D. Russo and AP Sports Writers Steve Megargee and Kareem Copeland contributed to this report.