William Perry, the Refrigerator, might have created a new position for himself here tonight -- the Sumoback.

The 325-pound rookie defensive tackle, a first-round selection who was called "a wasted draft pick" by Chicago Bears defensive coordinator Buddy Ryan in summer camp, ran for one touchdown and nearly disabled two Green Bay defenders while blocking for two more scores in Chicago's 23-7 victory over the Packers tonight.

The Bears, who joined the Los Angeles Rams as the only 7-0 teams in the National Football League, got 112 yards rushing from Walter Payton on 25 carries and chased three Green Bay quarterbacks into submission.

But nothing here tonight impressed the crowd of 65,095 like the performance of Perry, who redefined the concept of "blocking."

When Perry ran twice for four yards last week in Chicago's 26-10 victory over San Francisco, it was thought that his appearance as an offensive back was Chicago Coach Mike Ditka's way of getting back at Bill Walsh for a similar ploy last year.

But Perry participated in five more offensive plays tonight, twice knocking Green Bay linebacker George Cumby into the end zone (and the Twilight Zone) to spring Payton for touchdowns, and once forcing his way through the pile like some giant woolly beast for his score.

"No style, just straight ahead," Perry said afterward. "On the blocking plays, I had just one assignment: bump the linebacker -- and whoever got in my way, take them out, too."

Chicago, after trailing, 7-0, scored all three touchdowns in the first half and didn't score again until linebacker Otis Wilson sacked Jim Zorn for a safety late in the game.

"It feels wonderful, just marvelous to be where we are," Ditka said of his team's perch atop the NFC Central Division.

The Bears committed four turnovers in their first five possessions. But they came back to score three straight touchdowns to wipe out Green Bay's 7-0 lead and go ahead, 21-7, at halftime. Chicago's now-infamous defense protected the lead with six sacks of Lynn Dickey, Randy Wright and Zorn and also forced four interceptions.

The only possible downer for the Bears was the pounding of quarterback Jim McMahon, who was taken out in the fourth quarter after he aggravated a bruise on his buttocks. "He's really hurting," Ditka said.

McMahon, the NFL's top-rated passer coming into the game, did not throw a touchdown pass. But with Perry bolstering the Bears' running game, he didn't need to.

After an interception by Mike Richardson gave the Bears possession at the Green Bay 31 late in the first period, the fun started. Payton and Matt Suhey took turns running the ball and advanced it to the two, where the Bears called time out only a minute into the second quarter. When Perry trotted onto the field, the sellout crowd in Soldier Field grew hysterical.

It wouldn't be fair to call what Perry administered on the next play a "block." He lined up on the right side and obliterated Cumby, knocking him four yards deep in the end zone, which was plenty enough room for Payton to walk through for a two-yard touchdown as the Bears tied it, 7-7.

After a 47-yard punt return reverse by the Bears' Dennis Gentry, Payton fumbled at the Green Bay 12 after a nine-yard pass reception. But Dickey, who had been knocked out of the game once already, threw an interception on the next play.

Payton caught a pass for six yards, then ran 10 more to the one. The crowd knew what to expect, and Perry was greeted by a standing ovation. This time he was more than a decoy, going over the top for a one-yard touchdown with nine minutes left in the half as Chicago took a 14-7 lead.

There would be more before the half ended. The Bears worked carefully from their 14, taking 13 plays to get to the one. And that meant another look at Perry.

Cumby, a 224-pound linebacker, didn't need another look. Perry reduced him to Gumby on the next play and took two other Packers with him. Enough land was cleared for Payton to run in from one yard, making it 21-7 with a minute left in the half.