It's as easy as 1-2-3.

Number 1 Notre Dame needs a victory to retain its loftiest of perches.Number 2 Washington needs a loss by the Irish and a victory of its own to move up.

Number 3 Houston, on bowl-forbidden probation, would love another weekend of upsets that could give it - as the nation's only umblemished major college football team - the status of being on top despite all.

"I'm worried," Notre Dame coach Lou Holtz said of his team's clash Saturday with ninth-ranked Tennessee.

He should be, considering his Irish are one of four teams to have fallen from the top this season.

"I'm concerned with how we'll match up," Holtz said. "We haven't been able to hold many people to under 20 points, and yet it'll be difficult for us to score many points on Tennessee."

Should the Irish fail in their quest at Knoxville, Tenn., Washington would be the heir apparent with a victory when it hosts UCLA. Houston, which plays at No. 14 Texas, is next in line.

Elsewhere in games involving the Top 10, it will be No. 4 Colorado vs. Oklahoma State, No. 6 Iowa vs. Ohio State, No. 7 Georgia Tech vs. Virginia Tech, No. 8 Brigham Young at No. 25 Wyoming, and No 10 Florida vs. Georgia at Jacksonville.

Also, it will be No. 11 Virginia at North Carolina, No. 12 Florida State vs. Cincinnati, No. 13 Nebraska at Kansas, No. 15 Auburn vs. Southern Mississippi, No. 17 Illinois at No. 19 Michigan, No. 20 Oregon at California, No. 21 Penn State vs. Maryland, No. 22 Louisville vs. Boston College, No. 23 Southern Cal at Oregon State, and No. 24. Michigan State at Minnesota.

Holtz does have reason for concern. Notre Dame (7-1) allows 23.7 points per game and has held just two teams - Michigan State got 19 and Purdue 11 - below 20.

"We're giving up 25 points and nearly 400 yards a game," Holtz said. "I've never heard of a good team doing that.

"If there were answers to our defensive problems we would have found them before our ninth game."

The Irish offense, led by Rick Mirer and Rocket Ismail, is averaging 35.6 points and 434 yards per game. The offense has scored at least 30 points five times.

"This team is richly talented," Tennessee Coach Johnny Majors said of Notre Dame. "This is the kind of team that can blow you out, I don't care who you are.

"Lou will try to tell you they don't have the talent that a lot of other folks have, but they have a lot and it's well coached."

Tennessee (5-1-2) has an outside shot at the Southeastern Conference championship and its accompanying Sugar Bowl berth.

"The national championship will come if it's there," Washington cornerback Dana Hall said when asked where he thought the Huskies (8-1) might be in next week's poll. "It's on your mind, but you don't want to focus on one thing so much that you lose sight of what you really want to do. We just want to win our next game."

Washington clinched the Pac-10 Conference title and a Rose Bowl berth last week. But Hall, who intercepted a pass and blocked a punt last week in a 54-10 victory over Arizona, doesn't think the Huskies will have a letdown against UCLA (4-5).

"Everyone was really excited last Saturday," he said. "But we're relaxed now, and we're going to play more relaxed without the pressure of the Rose Bowl and the Pac-10 championship."

Mindful of NCAA sanctions, Houston Coach John Jenkins says the Cougars (8-0) have their own agenda.

"We said, `Let's administer the death penalty every Saturday we play,"' Jenkins said.

Houston views its game against Texas (6-1 overall and 4-0 in the Southwest Conference with the inside track to the Cotton Bowl) as its chance to show a national audience why it should be ranked first.

Advised that Jenkins had stated that Houston's run-and-shoot offense can't be stopped unless it stops itself, Texas Coach David McWilliams said, "I think he's got a pretty strong case."

And if the shoot is stopped, there's always the run. Texas knows all about Houston's Chuck Weatherspoon, who has run for 379 yards in the last two games against the Longhorns.