CARSON >> Ariel Lassiter brought the Galaxy crowd to its feet in the final seconds of the team’s season opener against FC Dallas on Saturday with a powerful left-footed shot. The excitement was short-lived, however.

The forward’s last gasp attempt was blocked and ricocheted wide of the net, dooming the Galaxy to a 2-1 loss to FC Dallas at StubHub Center.

Against the reigning Supporters’ Shield champions, the Galaxy pressed hard for a late equalizing goal and at times came within inches, but left haunted by several missed opportunities.

“I thought it was a game we shouldn’t lose,” coach Curt Onalfo said. “I thought we played well enough to get points out of the game.”

The Galaxy fired 12 shots to Dallas’ six, including eight in the second half, but were undone after conceding two soft goals.

FC Dallas caught L.A. in transition early in the second half. Maximiliano Urruti won the ball from defender Daniel Steres and threaded a shot through Jelle Van Damme’s legs to score in the 47th minute.

The Galaxy responded by earning a penalty kick five minutes later after defender Dave Romney was dragged down in the box. Forward Giovani dos Santos calmly buried the equalizing goal.

While building momentum, the Galaxy pressed forward in their attack. Dos Santos had a 20-yard attempt tipped over the bar by FC Dallas goalkeeper Chris Seitz. Jermaine Jones’ header off a dos Santos corner kick bounced off the post.

“I think if you watch the whole game, I think we controlled the game really good,” Jones said. “But at the end of the day, you have to score to win games.” The Galaxy gave up the game-winning goal to Kellyn Acosta, who threaded a right-footed shot after a throw-in inside the near post in the 69th minute.

Romney said the defense “fell asleep” on the throw-in.

Without former captain Robbie Keane and injured forward Gyasi Zardes, the Galaxy attack proved to still be potent. Offseason signee Romain Alessandrini combined with 22-year-old forward Jack McBean to test Dallas’ center back duo of Matt Hedges and Walker Zimmerman. McBean, who has been with the Galaxy organization since he was 16, deftly laid off passes for Alessandrini and dos Santos.

“You can see him growing as a young player,” Onalfo said of McBean. “He has a good physical presence playing against two very good central defenders.”

Alessandrini starred in his first MLS action. With only 45 minutes of official preseason experience under his belt, the French midfielder led the Galaxy with four shots while playing the entire game.

“The first half was good for me,” he said. “The second half, physically it was a little bit difficult. I think I need to come back step by step. I’m really disappointed about the result because we have a lot of expectations for this season. We need to win the games at home because it is the most important.”

The Galaxy started their new era by losing their first home opener since 2014. The offseason changes, which started with a brand new coaching staff and included the departures of two designated players, are still settling in. All three of the team’s major offseason signings — Jones, Alessandrini and midfielder Joao Pedro — made their Galaxy debuts Saturday in the starting lineup.

“We’ve added some really good pieces,” Onalfo said. “All the pieces we’ve added, they’re quality and you can see that in today’s game. It’s just getting it to gel and getting it to be fine-tuned.”