When the Home Depot Center in Carson opened the doors to its new soccer stadium Saturday at California State University, Dominguez Hills, two predictions came true.

First, about 27,000 enthusiastic soccer fans filed in to inaugurate a custom-built venue that adds a level of legitimacy to the popularity of a sport in a country that has mostly ignored it.

Second, they brought with them the traffic and congestion that many residents feared when the $150 million multisports center was first proposed more than three years ago.

But despite heavy pregame congestion along Victoria Street, Avalon and University boulevards, and the nearby 91 Freeway, Sheriff’s Department officials and some residents said things went smoothly.

“It’s kind of a learning experience for us,” said sheriff’s Sgt. Ken Fitzpatrick, who oversaw the event’s traffic and crowd control. “I think overall the plan worked well, it just (needs) a few refinements. . . . The thing is, when you have (about) 25,000 people coming to an event, you’re going to have some congestion.”

Fitzpatrick said about 10 cars were towed from the surrounding neighborhood, but sheriff’s patrol cars and barricades kept most soccer fans out. He added that during future events, they will use better signage to direct fans to parking.

A resident of a nearby mobile home park said that stadium goers mistakenly entered the Avalon Boulevard property to park and broke the arm off of a traffic barricade.

Inside the stadium, where fans were either roaring in their seats, chasing hot dogs down with gulps of beer or checking out the new digs, it didn’t seem to matter how long it took to get in to watch the Los Angeles Galaxy beat the Colorado Rapids, 2-0.

Hugo DeLeon and his family traveled from Palmdale to watch the Galaxy’s home stadium debut.

“When you’re a fan of soccer, you go everywhere,” DeLeon said, adding that the new venue is a far cry better than the team’s old home, the Rose Bowl in Pasadena. “I like it because it’s just for soccer games.”

Many in the crowd were sporting various items of Galaxy paraphernalia, from jerseys and hats to flags draped across their backs like capes.

Kevin Graham wore a giant rubber soccer ball mask as he walked around with three young soccer players, including his son, from his hometown of Aliso Viejo.

A soccer player all his life and a holder of season tickets for the new stadium, Graham said he liked it better than the Rose Bowl, a sentiment expressed by many.

“I think it’s more intimate. There’s not a bad seat in the house,” he said. “. . . I think it will draw a whole new fan base, which will be better from a family standpoint.” Earlier, Billy McNicol, a former professional soccer player with one of Scotland’s most famous teams, Glasgow Rangers, sat sipping beer on the Stadium Club’s outdoor patio overlooking the field.

McNicol coaches youth soccer in Orange County after also playing in several now defunct American predecessors to Major League Soccer.

“It’s much more family-friendly (than Scotland),” said McNicol, who recalled the sometimes dangerous atmosphere that permeated games in his homeland. “At the end of the day here the game’s getting respect — we used to be a novelty.”

Indeed, the birth of a proper soccer stadium in the South Bay has drawn out a number of fan groups and their members, including Redondo Beach resident David Hudson, a member of the L.A. Riot Squad.

Hudson, 28, said the atmosphere promised with the opening of the stadium, so tepid at many Major League Soccer games, was delivered in a cozy design with roofs that add to the decibel level.

“You could really hear a palpable roar throughout the game,” said the director of production at a software company. “My main hope is that the interest keeps up with the venue and hopefully every game going forward has the same level of excitement and novelty today had.”

While fans inside the stadium cheered a penalty kick goal by the Galaxy in extra time, residents outside prepared themselves for the postgame rush, which, like most of the day’s congestion, moved slowly but smoothly.

Capt. Gerry O’Hagan, at the county fire station across Victoria Street from the center, said that although traffic flow could be improved, no major problems occurred.

“We actually did run a response (after the game) and we weren’t delayed, but obviously this is more traffic than we usually encounter out here,” O’Hagan said. The call occurred in the stadium’s parking lot and the firetruck had trouble getting in through all the exiting cars, he said.

As law enforcement, residents, fans and stadium officials round the beginning bend of the learning curve, there is no arguing that Major League Soccer has come to the South Bay.

Its thousands of fans, players and their cars speak volumes.

“If you call yourself a soccer fan and don’t make a pilgrimage to come out here then you are not a soccer fan — you are a phony, an imitator,” said Sigi Schmid, Galaxy coach and longtime South Bay resident. “You could put this stadium anywhere in Europe or South America and anybody would be proud to have this place.”