SAN FRANCISCO – Up on the scoreboard the clock showed only 58 seconds remaining in the National Conference Championship game today, but at the 49ers’ sideline during their timeout, Coach Bill Walsh was talking to his quarterback, Joe Montana, as calmly as if it were the first day of training camp. And in a sense it was the first day of training camp.

“That play was nothing special,” Bill Walsh would say later. “It’s a play we practice from Day 1 in camp.” Practice makes perfect. As the timeout was about to expire now, Joe Montana trotted out to the huddle. With a third-and-3 at the Dallas Cowboys’ 6-yard line and trailing, 27-21, the 49ers could not afford any more turnovers. At the snap, Joe Montana moved out toward the right sideline. Quickly, he looked for Freddie Solomon, but then he noticed his other wide receiver, Dwight Clark, alone in the back of the end zone.

“I was getting pressured,” Joe Montana said later, “but they weren’t on top of me. I had a little room.” But when Joe Montana threw the pass, he threw it “off the wrong foot,” as coaches say, meaning off balance. It did not matter. The ball spiraled high into Dwight Clark’s hands near the back line of the end zone. And when Ray Wersching added the extra point, the 49ers had a 28-27 victory that put them in Super Bowl XVI against the Cincinnati Bengals a week from Sunday at the Pontiac Silverdome.

“We’re not overwhelmed by it,” Joe Montana was saying now at his locker. “But we are excited about the honor of playing in the Super Bowl.”

Joe Montana never appears to be overwhelmed by anything. And perhaps that’s why he’s been so successful so quickly. In only his third season, he has passed the National Football League’s most frustrated franchise into an opportunity to “win it all” for the first time since the 49ers were founded in 1946 as a member of the All- America Conference.

Until today, the 49ers had never won more than a division title. And only three of those. But now they are the N.F.C. champions for the first time. And in two weeks they have a chance to win the N.F.L. title for the first time in Super Bowl XVI.

Nobody understood that any better today than two former 49ers – John Brodie, once their quarterback, and O.J. Simpson, who grew up here on Potrero Hill before emerging as a renowned running back with the Buffalo Bills and ending his career with the 49ers three seasons ago. Today they were sitting together when Joe Montana threw the pass for the winning touchdown. “John Brodie was crying,” O.J. Simpson said later. “And he was raving about Joe Montana, saying that there isn’t a quarterback in the league who can do what he can do, especially the way he throws off balance.”

These are the 49ers of Joe Montana and Dwight Clark and Freddie Solomon and Bill Walsh, who is considered to be the N.F.L.’s newest “offensive genius.” And week after week, Bill Walsh is justifying that description. “We drove 90 yards for a touchdown when we had to have it,” the 49er coach said. “And to me, that is the vital essence of the National Football League.”