The elite of the NFL, either through good timing or relentless efficiency, found the way to do what they were supposed to do Sunday - win.

The San Francisco 49ers trounced, the Chicago Bears escaped with an overtime field goal; in two shutouts, the Buffalo Bills didn't seal the victory until 98 seconds remained and the New York Giants were never threatened.As a result, the NFL still has two 10-0 teams and two 9-1 clubs entering the Monday night game featuring the 8-1 Miami Dolphins.

"One really positive thing is we are moving forward," San Francisco linebacker Matt Millen said after the unbeaten 49ers trampled 4-7 Tampa Bay 31-7. "We are not going back and this is the time of the year to do it."

With the hurdle ahead in their mission of an undefeated season, the Giants took advantage of a lesser challenge in a 20-0 defeat of the Detroit Lions, 3-7. Now, the teams get tougher and motivation becomes easier.

"I told them I'm not worried about getting ready to play anymore," Parcells said. "Because the level of competition will take care of itself."

New York plays at Philadelphia next week, then visits San Francisco in a game that has received a two-month buildup, since the Giants and 49ers became the only remaining undefeated teams on Oct. 7.

The 49ers became the third team in NFL history to win 18 straight games spanning two seasons. Joe Montana became the first player to throw for 3,000 yards in seven straight seasons and Roger Craig rushed for his 50th career touchdown but the 49ers focused on this year's quest.

"We're playing better every week," tight end Brent Jones said. "I think in the next couple weeks, we're going to have to take it up to the great level."

The Giants play Buffalo at home Dec. 15 in a game that could offer close to the same level of competition as New York-San Francisco, if not the same hype.

The Bills, who blanked New England 14-0, have not lost since the second week of the season at Miami. Buffalo needed a goal-line stand, two interceptions and four sacks along with Thurman Thomas's two touchdowns against the 1-9 Patriots.

The Bears, 9-1, beat the Broncos, 3-7, on Kevin Butler's 44-yard field goal with 1:46 remaining after he missed a 41-yard kick as regulation expired. Chicago has won five games since its only setback, against the Raiders.