Atlanta United defender Franco Escobar, left, celebrates with Jeff Larentowicz after scoring in the second half. (Dale Zanine/USA TODAY Sports)

ATLANTA — There was a time not so long ago when spectators without rooting interests would leave an MLS Cup played at a neutral site before the final whistle. It was a bad look for the league and part of the impetus in 2011 to switch to home-field advantage.

On Saturday, in a year-old starship that will stage the Super Bowl in eight weeks and Final Four in 16 months, MLS never looked better.

Standing from start to finish — and then some in celebrating the city’s first major trophy since 1995 — a championship-record crowd of 73,019 at Mercedes-Benz Stadium watched Atlanta United cap an extraordinary first two seasons in MLS with a 2-0 victory over the Portland Timbers.

Venezuelan Josef Martinez, the league’s leading scorer and MVP, struck late in the first half and assisted on Argentine defender Franco Escobar’s goal early in the second. And 50 years after the Atlanta Chiefs won the first North American Soccer League crown, United basked in the sport’s incredible growth in this gridiron stronghold.

Atlanta is “one of the great stories in the history of our league and, in my opinion, one of the great stories in professional sports,” Commissioner Don Garber said a day earlier. “Their success shows that there really is no limit to what MLS can be.”

The home side embraced the moment, unleashing its league-best attack and corralling a Portland team that had beaten the odds throughout the postseason.

An all-day cold rain seemed like a good omen for weather-tested Portlanders, who dressed in woodsy green hues and numbered more than 1,300. The victory log, ceremoniously sliced by chainsaw-wielding Timber Joey after home goals, arrived via cross-country truck.

This backdrop, though, was a celebration of Atlanta’s embrace of soccer, reward for playing stylish soccer in finishing with the second-most points in the regular season before defeating the front-running New York Red Bulls in the Eastern Conference finals.

Except for the artificial turf, it was a dream setting for a city often disparaged for not supporting its teams, for a league that continues to reach new heights and for a sport that is gaining a mainstream foothold.

Said game MVP Martinez: “I just want to thank everybody — the coaching staff, the players, the fans, the city because I know it’s been a long time since they’ve had a championship and they deserve it.”

Few soccer matches around the kick-happy world this weekend would eclipse Atlanta’s attendance figure.

With an attack that hums on fast surfaces and features the two top finishers in MVP voting, Atlanta entered as the clear favorite. The Timbers were the No. 5 seed in the six-team Western Conference playoffs, but three years after winning their first title, they showed their postseason chops by upsetting Dallas, Seattle and Kansas City.

Atlanta’s Miguel Almiron, a Paraguayan rumored to be heading to Europe this winter, threatened in the 29th minute, his side volley turned aside by goalkeeper Jeff Attinella.

Martinez, who scored a record 31 goals in the regular season, broke through 10 minutes later, wheeling around Attinella for a simple deposit into an unprotected net.

The sequence began 40 yards away. Atlanta defender Michael Parkhurst pressured Jeremy Ebobisse into what was either a deflection or a haphazard back pass. At the top of the penalty area, with Martinez off his shoulder, Portland defender Liam Ridgewell stabbed at the ball unsuccessfully.

Martinez was alone for the sure goal.

But was he offside? No. You can’t be offside on a back pass and, if Parkhurst was last to touch it, a Portland outside defender was keeping Martinez in a legal position.

Atlanta’s Brad Guzan preserved the lead before halftime with a fine save on Ebobisse’s six-yard header.

Early in the second half, the Timbers seize control amid Atlanta problems.

“When you play away in a stadium like this, it is always more difficult,” Timbers Coach Giovanni Savarese said. “It was a motivation for us. We weren’t afraid of the occasion and actually we started to play and did some very good things.”

But the good vibes did not last long.

In the 54th minute, Almiron served a free kick from 30 yards. Martinez won the header amid lax marking in the heart of the box, flicking the ball to right back Escobar on the back side for a three-yard stab past Attinella.

In swift fashion, the momentum had shifted back to Atlanta, and with it, Portland’s hopes of winning in a raucous environment faded.

With giant flags waving and sections behind the goal bouncing, a team and city prepared to celebrate the first championship since the Braves won the World Series 23 years ago.

Almost two years after his Falcons collapsed in the Super Bowl against the Patriots, United owner Arthur Blank raised the MLS trophy.

And for Coach Gerardo Martino, who announced this fall he would leave the club (and probably join the Mexican national team), it was a fitting exit.

“If I had to chose how to leave,” he said, “this is the best way.”

As for United, “This isn’t the ceiling.”

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