Roger Staubach of the Dallas Cowboys, demonstrated once more today why this is known as the era of the mobile quarterback.

The former naval officer also had to make the right command decision in a crisis as Minnesota linebackers Matt Blair and Jeff Siemon stared him in the face on the last play of a sudden-death game.

Staubach looked to see if his tight end Jay Saldi, was open in the end zone as he rolled out from the Minnesota four-yard line.

Saldi wasn't open. Blair was closing in and Staubach opted to exercise the run option of his rollout.

He made Blair miss and gave it just enough of a burst when Siemon tackled him at the goal line to score the touchdown that gave the Dallas Cowboys a 16-10 victory.

"I wasn't going to throw the ball unless Saldi was wide open," Staubach said. "It was a trap play with a rollout."

Sure, another down and 3 minutes 46 seconds remained so there would have been no sweat about getting Efren Herrera in there for what would have been pretty much automatic field goal distance. But Herrera had missed a 27-yarder with three seconds left in regulation time that would have won the game a lot earlier.

Remarkably, in view of preseason expectations concerning Heisman Trophy winner Tony Dorsett, the Cowboys won this season opener with no help from him.

The rookie from the University of Pittsburgh with the five-year, $1.1 million contract was not called upon until 22 minutes and 40 seconds had been played in the first half. It was the first time in a regular season that he had not started a game, going back to his high school days.

On his first carry today, with the Cowboys behind, 7-3, Dorsett shifted into the tailback position in the I information and scuffled for a three-yard gain. On his next attempt however, he was thrown for a yard loss by 39-year-old defensive end Jim Marshall.

Dorsett faced a third-and-two challenge in the same series and took off on one of his familiar sweeps off the right side. He eluded one tackler before he was stopped without gain by Siemon and left cornerback Nate Wright forcing the Cowboys to punt.

On the next Dallas possession, Dorsett's signal was called on a draw play on second and 10. He accelerated quickly and had a nine yard gain, but he fumbled the ball forward and safety Jeff Wright recovered for Minnesota. That ended Dorsett's work for the day.

Coach Tom Landry said he had planned to use Dorsett more if the game had not been so close.

"I'd like to see him get experience, but that wasn't a good day out there to get experience," Landry said. "It was such a critical point spread in the second half that we had to use Preston Pearson.

"Tony is going to be a great player, and we will use him more and more as the season goes on."

Preston Pearson was the reason the Cowboys stayed close.

He averaged 4.2 yards on 15 carries in this raging defensive struggle and caught five passes for 53 yards, including the seven-yarder for a score in the fourth quarter that put the Cowboys ahead for the first time, 10-7.

After the Vikings' Fred Cox kicked a 35-yard field goal for a 10-10 tie and Herrera missed a 27-yarder to send the game into overtime, Minnesota won the coin toss and, of course, chose to receive.

That is when the Dallas defense rose to the occasion.

Quarterback Fran Tarkenton came up to second-and-seven at the Minnesota 45 and was chased so hard by defensive end Harvey Martin that he was guilty of obvious grounding of the ball.

On his next passing attempt, Tarkenton was sacked for a nine-yard loss, again from behind, by defensive tackle Larry Cole. Neil Clabo was punting on fourth and 31 from his 21 when he got off a ghastly shank that carried only 26 yards, out of bounds.

Staubach then seized on the disarray of the Vikings to complete three straight passes - 77 yards and then four more to wide receiver Drew Pearson and a screen pass to wide receiver Golden Richards, who stretched it to 11 yards.

Robert Newhouse ran for six and Preston Pearson added five on two carries. On third down, Staubach accounted for the final four on a day when the Redskins and St. Louis Cardinals already had lost.

Tarkenton managed an 18-yard touchdown pass in the first quarter to running back Chuck Foreman, who gained 66 yards on 22 carries and caught five passes for 56 yards, but the 10-point offensive performance infuriated defensive end Carl Eller.

In the Minnesota dressing room after the game, in a speech chastizing the offense, Eller said:

"The defense plays well and everybody expects us to win the game. It happens every game, it happens every season: to me that doesn't make much sense."