The Dallas Cowboys are no longer the bumbling bunch that struggled through the first half of the National Football League season. They are for real now and they proved it yesterday with a near perfect performance in a 27-7 rout of the New Orleans Saints.

The victory may prove to be costly, however, as fullback Robert Newhouse broke a bone in his right leg and with be lost indefinitely.

The Cowboys did not commit a turnover and were in touchdown territory at the end, letting the clock run out while they were at the New Orleans one-yard line.

The victory which came about an hour after St. Louis upset the Redskins, 27-7, in Washington, leaves the Cowboys and Redskins tied for first place in the NFC East with 8-4 records, and makes the Thanksgiving Day showdown between the two at Texas Stadium about as important as a regular-season game can be.

The Cowboys cannot wait.

"We tried not to look past this game today, but it was tough," said wide receiver Drew Pearson. "We were thinking Redskins all day."

"I just hope they don't miss their plane Wednesday on the way down here," said defensive end Harvey Martin.

"The turkeys are gonna have to come on in here and we're waitin' for them," added linebacker Thomas Henderson.

The Cowboys tried their best to give the Redskins their respect, but it was obvious that they want not only to win the game, but to destroy the Redskins as well.

Their celebration was clouded with the news that Newhouse suffered a fractured fibula and will be lost for at least the next two games.

Coach Tom Landry said the fireplug back has been the most consistent Cowboys offensive player this season. Newhouse suffered the injury on the Cowboys' first possession of the game.

Scott Laidlaw played most of the game at fullback and Landry said Laidlaw would start Thursday.

The Dallas offense today was Tony Dorsett. He carried 25 times for 152 yards and scored one touchdown. He also had a 63-yard run to set up another score.

The rushing total gives Dorsett 1,020 yards for the season.

"Tony is running hard and if we give him the ball 20-25 times a game, he'll break one. He broke one on the 20th carry today. That makes for an easy day for me. All I have to do is hand the ball to him," said quarterback Roger Staubach.

It was a very physical game and the Cowboys established early that they weren't going to be pushed around, something they had allowed to happen to them earlier in the season.

New Orleans took the opening kickoff and Archie Manning, the NFC's leading passer, took the Saints 73 yards to a score in 12 plays, consuming the first six minutes of the game. Manning completed four of five passes for 50 yards on th drive.Chuck Muncie got the touchdown on a one-yard run.

On Dallas' second possession, Dorsett swept around his right end for 13 yards. He was wrestled out of bounds and bulldogged to the ground by Clarence Chapman in front of the Cowboy bench.

A minor melee broke out as practically the entire Cowboy team converged on Chapman. A few punches were thrown, but no one was ejected. The Saints were assessed a 15-yard penalty. The Cowboys didn't score on that possession, but they did on their next three.

"That fight got us going," said Martin. "The game was over right after that."

There were two other near brawls yesterday, one even involving the usually sedate Staubach.

Kick-return specialist Butch Johnson was ejected in the third period for "throwing the ball in an opponent's face."

The defense set up Dallas' first two scores. Henderson stole the ball from Tony Galbreath as he tackled him in the second quarter, giving the Cowboys the ball at the Saint 33.

Five plays later, Dorsett ran two yards for Dallas' first touchdown.

On New Orleans' next possession, Martin unloaded on Manning as the Saint quarterback was trying to throw a pass and the ball plopped into the hands of the Cowboys' Larry Cole at the New Orleans 39.

A 24-yard Staubach-to-tight-end-Billy Joe DuPree pass on the Cowboys' first possession of the third quarter increased their lead to 21-7.

Two fourth-quarter Rafael Septien field goals ended the scoring.

The Cowboys looked nearly unbeatable last week against Green Bay, too, and now with two superb games in a row, it appears the old Super Bowl fire is back.

"It better be, because it's that time, now,"said Martin.