In one night, the Rams vindicated two off-seasons’ worth of bold personnel moves intended to turn a middling team from St. Louis into a champion in Los Angeles. Having pierced the aura of the Superdome, where Payton and quarterback Drew Brees had won their previous six playoff games, the Rams will now face New England on Feb. 3 in Atlanta.

It is not a surprise that the Patriots – who also advanced with an overtime victory, by 37-31 at top-seeded Kansas City – will be there. They always are. But the Rams have gotten this far because, at bottom, every move they made after losing to Atlanta in the playoffs last year, all the off-season splurges and in-season roster churn, positioned them to thrive amid the jackhammer-in-your-ear din that they confronted on Sunday in the Superdome.

“We didn’t feel pressure,” said cornerback Aqib Talib, one of several new players on the Rams’ revamped defense. “We applied it.”

This N.F.C. title-game matchup registered somewhere between sunrise and sunset on the inevitability scale. Since September, New Orleans and Los Angeles had jockeyed for the conference’s top seed, with one coaching mastermind named Sean striving to duplicate the success of another. No other matchup embodied the season’s offensive boom better than having the conference’s most prolific teams — who combined for 80 points in the Saints’ Week 9 home victory over the Rams — vying to outscore each other for a second time.

On Sunday, a full quarter elapsed before the Rams looked comfortable — or, at least, they no longer looked sleeping-above-an-alligator-pit uncomfortable — and then gradually, they chiseled away at the Saints’ lead. They trailed by 13 after the first quarter but by just 3 at halftime and ultimately tied the score, at 20-20, on Zuerlein’s 24-yarder with 5:03 left in the game.

The other day in the Saints’ cafeteria, Brees, newly 40, glanced up and saw himself on television. The channel was showing the N.F.C. championship game from 2010, the last time New Orleans played in the Super Bowl. His teammates ribbed him about all the hair he had nine years ago, all the hair he seems to have lost.

Seizing the chance Sunday to lead them to another, Brees drove the Saints to the Rams’ 13. On third-and-10, Lewis scooted out of the backfield and ran a wheel route. Brees saw him and released a pass down the near sideline — the Saints’ sideline — toward Lewis, who was now inside the 5-yard line. The ball never reached him. Robey-Coleman made certain of that.