Every so often there's a Saturday to remember in college football, when just a few games determine the course of the season.

On Saturday, for the first time in 26 years and just the fourth time since 1936, when the AP poll began, four of the top five teams are matched against each other on the same day - No. 4 Michigan at No. 2 Penn State and No. 3 Florida State at No. 5 North Carolina.What's more, all four have perfect records.

At State College, Pa., there are implications for the Big Ten title, the Rose Bowl and the national championship when the Nittany Lions (7-0, 4-0) and Wolverines (8-0, 5-0) play before a Beaver Stadium crowd of 97,000 (ABC, 3:30 p.m. EST).

At Chapel Hill, N.C., the stakes might be even higher when the Tar Heels (8-0, 5-0) play the Seminoles (8-0, 6-0) at 60,000-seat Kenan Memorial Stadium (7:30 p.m. EST, ESPN). If the winner finishes with a perfect record, an Orange Bowl berth awaits, and so might No. 1 Nebraska (8-0) in what could be the national title showdown.

Both favorites - Penn State and Florida State - have major concerns going in: Too many mistakes for Joe Paterno's guys, a missing defense for Bobby Bowden's troops.

"We're going to find out how good a football team we are, whether we can play better than we have been, whether we can play smarter," Paterno said, referring to numerous penalties and poor pass protection in a 30-27 win over Northwestern last week.

The Lions, led by Curtis Enis' 830 yards and 12 touchdowns, have won their last three games by a total of eight points after outscoring their first four opponents 184-54.

With cornerback Charles Woodson leading the nation's top defense (202.5 yards, 7.5 points per game), the Lions have little room for error.

The Seminoles may be 7-0-1 against the Tar Heels, but Bowden can't figure out how his top-notch defense - dropping from No. 1 to No. 4 overall - allowed N.C. State to roll up 448 yards and five touchdowns in FSU's 48-35 win last week.

"Scares me to death," Bowden said. "Right when you think you have a lock on things, you lose it. I can't explain it. I don't know what it means."

Coach Mack Brown knows first-hand how well the Seminoles' defense can play. Last season, Florida State beat North Carolina 13-0.

While the Tar Heels have the nation's second-ranked defense (206 yards per game), the offense has a few weapons, too. Oscar Davenport is 111 of 173 for 1,330 yards and six TDs, while Jonathan Linton has 708 yards and seven TDs.

Florida State counters with Thad Busby (171 of 286 for 2,543 yards and 18 TDs), freshman Travis Minor (61 carries, 357 yards and eight TDs) and leading receiver E.G. Green (38 catches, 825 yards and eight TDs).

"It's step up or shut up time," Tar Heels linebacker Kivuusama Mays said.