SEATTLE — Bob Bradley was beaming. Brian Schmetzer was stewing. Several of the Seattle Sounders FC players were ailing. And it all added up to an inauspicious start to the 2018 MLS season for the Sounders.

Seattle, seeking a third straight trip to the MLS Cup final, kicked off its MLS campaign Sunday afternoon at CenturyLink Field against the league’s newest expansion team, Los Angeles FC. However, LAFC refused to play the role of the deferential newcomer, knocking off the two-time defending Western Conference-champion Sounders 1-0.

Diego Rossi scored an 11th-minute goal, and LAFC withstood a 79-minute Sounders barrage to become the fifth MLS expansion team in 16 attempts to win its debut.

“That’s a great win,” said Bradley, LAFC’s coach. “The first 25 minutes I thought actually the football was pretty good. After that it was about fighting and defending. But when you’re starting out as a team, you have to learn how to win different kinds of games, and a lot of guys gave big efforts.”

Seattle, missing several key players because of rest or injury — star forward Clint Dempsey and defensive stalwart Chad Marshall were both held out in anticipation of Wednesday’s CONCACAF Champions League quarterfinal game against Mexican power CD Guadalajara — dominated the statistical categories, holding a 22-5 advantage in shots and 12-1 edge in corner kicks. But the Sounders were on the wrong side of the only number that mattered.

“The team never gave up,” Schmetzer, Seattle’s coach, said. “We got a man sent off and they continued to press forward to try and get the tying goal. There was never a second where we didn’t see the effort they put into the game.

“We understood that was their first game and that they were going to play and be lively,” Schmetzer added. “I think other than that goal, which was a well-crafted goal in some sense, I thought it was even. It did take us a while to get into it, but once we got a hold of the game, I thought we were real dangerous and created a ton of chances.”

Seattle could have found itself behind just 65 seconds into the game as LAFC’s Latif Blessing put a header off the post. But LA did grab the lead in the 11th minute. Carlos Vela slipped a touch pass through for Rossi, who curled a right-footed shot from just outside the penalty box around diving Sounders goalkeeper Stefan Frei and into the right corner for a 1-0 lead.

After that, all the quality scoring chances fell to the Sounders. LAFC goalkeeper Tyler Miller made a good diving stop to his left to tip Nouhou’s volley attempt around the post, Nicolas Lodeiro had time to line up a shot inside the penalty box but fired wide, Harry Shipp had a goal-bound shot tipped over the crossbar by sliding LAFC defender Laurent Ciman, and it remained 1-0 at halftime.

It was more of the same in the second half as the Sounders continued to create premium scoring chances, but failed to finish them. Handwalla Bwana had a shot deflect off the crossbar, Bruin had a header in the net but was judged to be offsides, Cristian Roldan had a header from a corner headed into the top corner only to be palmed away by Miller.

Even after Seattle defender Tony Alfaro was ejected in the 84th minute following his second yellow card, it was the Sounders who seemed to be playing up a man, continuing to create chances. But when Lamar Neagle’s header from a corner went wide in the 89th minute it was clear it wasn’t Seattle’s day.

Spot kicks

Sunday’s game was a homecoming for Miller. LAFC’s goalkeeper, who spent the previous two seasons serving as Frei’s backup with the Sounders, was the first selection in the expansion draft. However, midfielder Aaron Kovar, on loan from Seattle to LAFC this season, was ineligible to play against his parent club. … In addition to Dempsey and Marshall, the Sounders were without several projected starters. Forward Jordan Morris is out for the season after suffering a torn anterior cruciate ligament in his knee. Midfield anchor Osvaldo Alonso (quadriceps) and right back Kelvin Leerdam (ankle) were ruled out before the game, and attacking midfielder Victor Rodrugiuez (quadriceps) was also left out after being listed as questionable. Then central defender Roman Torres was taken off at halftime with an eye toward Wednesday’s game.

Sounders’ midfielder Magnus Wolff Eikrem attempts a shot with Los Angeles’ goalkeeper Tyler Miller diving in on the Xbox Pitch at CenturyLink Field Sunday afternoon in Seattle on March 4, 2018. Los Angeles FC won 1-0. (Kevin Clark / The Daily Herald)

Los Angeles’ goalkeeper Tyler Miller gathers a shot with Sounders’ defender Romn Torres (center) and Los Angeles’ Mark_anthony Kaye (left) looking at CenturyLink Field on the Xbox Pitch Sunday afternoon in Seattle on March 4, 2018. Los Angeles FC won 1-0. (Kevin Clark / The Daily Herald)

Sounders’ midfielder Gustav Svensson slides to advance with Los Angeles’ defender Tristan Blackmon defending on the Xbox Pitch at CenturyLink Field Sunday afternoon in Seattle on March 4, 2018. Los Angeles FC won 1-0. (Kevin Clark / The Daily Herald)

Sounders’ forward Will Bruin reacts to a waved off goal on the Xbox Pitch at CenturyLink Field Sunday afternoon in Seattle on March 4, 2018. Los Angeles FC won 1-0. (Kevin Clark / The Daily Herald)

Sounders’ midfielder Henry Wingo (left) vies for the ball with Los Angeles’ defender Joo Moutinho on the Xbox Pitch at CenturyLink Field Sunday afternoon in Seattle on March 4, 2018. Los Angeles FC won 1-0. (Kevin Clark / The Daily Herald)