Mississippi State, Florida State and Auburn held the top three spots in the second College Football Playoff rankings, with Oregon joining them in the top four Tuesday night.
Marcus Mariota and the Ducks, coming off a 45-16 win over Stanford, moved up one spot from fifth in the initial poll by the 12-member selection committee. They moved in ahead of Alabama, a third team from the West Division of the Southeastern Conference that was also up one place to fifth.
''It was very close, and I think it's the product of Oregon's other wins they have,'' Arkansas athletic director and selection committee chairman Jeff Long said. ''They have the Michigan State win, but they also, again, went on the road against UCLA and won, and a couple of wins that made their body of work, put them a step ahead of (Alabama) at this point.''
Mississippi dropped seven spots to 11th after its second consecutive loss, 35-31 to Auburn. The Rebels remained ahead of four one-loss teams from power-five conferences, directly ahead of Baylor, Nebraska and Ohio State - Nos. 12-14, and all higher than a week ago.
Auburn is the highest ranked of the 12 one-loss teams in the rankings that will ultimately determine the national semifinals, and set matchups for the other four marquee New Year's Day bowls that are part of the playoff rotation.
Mississippi State held on to No. 1 after a 17-10 victory over Arkansas, when the Bulldogs trailed after halftime for the first time this season. Florida State overcame a 21-0 deficit at Louisville and won 42-31.
The Bulldogs and Seminoles are the only remaining undefeated teams from power-five conferences, and Long said ''it really wasn't close'' to any chance of them flip-flopping in the top two spots.
''We stayed pretty consistent with the way we looked at 1 and 2 with Mississippi State and Florida State,'' Long said. ''Auburn was a little bit behind in No. 3, but they were a solid No. 3.''
Marshall, which is 8-0 in Conference USA, again didn't make the Top 25 playoff rankings.
Big 12 leader Kansas State moved up two spots to seventh, hopping over Michigan State, which remained eighth.
''Less about Michigan State, but more about Kansas State adding to their body of work,'' Long said, referring to the Wildcats, who are coming off a 48-14 win over Oklahoma State.
Kansas State plays at TCU on Saturday night, and Oregon is at Utah, which stayed 17th in the playoff rankings after a 19-16 loss at Arizona State.
The Sun Devils made the biggest upward move, five spots to ninth. That is one spot ahead of Notre Dame, which rounded out the top 10 for the second week in a row, and plays at Arizona State on Saturday.
The final playoff rankings will be released Dec. 7, the day after most of the conference championships are decided.