Quarterback Steve Fuller, subbing for the injured Jim McMahon, ran for two touchdowns and Chicago's defense forced four turnovers to help the Bears remain undefeated with a 24-3 victory today over the Detroit Lions.

The victory gives Chicago (10-0) a five-game lead in the NFC Central with six to play. It is the Bears' best start since the 1942 team won all 11 of its regular-season games. Chicago is the first NFL team since Minnesota a decade ago to win its first 10 games.

The Lions fell to 5-5.

Chicago's Walter Payton rushed 26 times for 107 yards and Matt Suhey ran 16 times for 102 yards. It was Payton's 69th career 100-yard-plus game and his fifth straight. The last time two Bears back went over 100 yards was in 1983 against Tampa Bay when Suhey gained 112 and Payton 102.

"It was old-fashioned football, old-fashioned Bear football," Payton said. "Take the ball to 'em."

Chicago outgained Detroit on the ground, 250 yards to 68.

The Bears didn't even need William (The Refrigerator) Perry as an offensive weapon. He blocked on three plays, but he didn't carry the ball or catch a pass all day.

"That's all right with me," said Perry, who was in on two sacks in his second start at defensive tackle. "You can't run all the time. You have to block some."

Bears linebacker Mike Singletary recovered two fumbles. The Bears intercepted two passes and sacked quarterback Eric Hipple four times for losses totaling 35 yards.

"The weather conditions were devastating," said Fuller about the blustery, rainy day. "The toughest thing to do is play the Chicago Bear defense on a day like this. But you have to give the credit to the guys who went over 200 yards and the offensive line."

"It's very hard to throw the football deep under those conditions," said Chicago Coach Mike Ditka, who had given Fuller the game plan Friday. McMahon did not play because of a shoulder injury.

"I took the game plan home and circled the plays I thought I would like best," Fuller said. "I didn't change anything, I just narrowed it down."

Fuller scored on a one-yard run in the first quarter following Dave Duerson's interception and scored on a five-yard run in the third quarter. Calvin Thomas scored on a seven-yard run late in the second quarter.

Detroit's lone score came after cornerback Bobby Watkins recovered Fuller's errant pitchout to wide receiver Willie Gault midway through the third quarter. But the Bears forced the Lions to settle for Ed Murray's 34-yard field goal with 5:01 left in the period to close the gap to 14-3.

The Bears then launched their most impressive drive of the game against a 17-mph wind. Fuller (seven of 13 for 112 yards) connected with Payton for 22 yards and Tim Wrightman for 23 yards to set up Fuller's five-yard score.

Kevin Butler, who earlier missed a 43-yard attempt, made a 39-yard field goal with 5:42 left after an interception by linebacker Otis Wilson.

"Chicago is the class of our division," Detroit Coach Darryl Rogers said. "But we're still 5-5 as miserable as we looked today. As long as we stay healthy, we still have a chance at a wild-card spot."

"It's embarrassing," said Lions tackle Keith Dorney, who played with a broken big toe. "They came in and blew us out. What can I say? I'm very embarrassed."