Landon Donovan volleyed home a goal in the 60th minutes off an assist from David Beckham to help the Los Angeles Galaxy beat Honduras club Motagua 2-0 in Tuesday's opener of CONCACAF Champions League group play.
Adam Cristman scored on a sliding finish in the 13th minute for Los Angeles, which got to skip the preliminary round for winning the MLS Supporters' Shield last season.
"It's crucial," Donovan said. "We talked about it all week. Tonight was the first step in the right direction."
The Galaxy were eliminated in the preliminary round by the Puerto Rico Islanders a year ago.
On the first goal, Juninho started the sequence with a through ball into the box. A.J. DeLaGarza used one touch to cross it through the box to a charging Cristman, who finished into the empty net.
Beckham set up the Galaxy's second goal, playing in a ball from the right wing that sailed to the far post and landed at Donovan's feet, where he played it after one bounce.
The Galaxy won the Champions Cup in 2000 under the tournament's old format, which has since adopted a group stage.
"This competition is going to be difficult," Galaxy coach Bruce Arena said. "There are five more tough games in group play. Every game, every goal, every minute is going to require our upmost concentration."
In the other Group A match, Costa Rica's LD Alajuelense earned a 1-0 win against Morelia of Mexico.
Seattle Sounders fought back from conceding an early goal to crush Comunicaciones 4-1 in Group B.
Jairo Silva gave the Guatemalan side the lead after just two minutes, but Brad Evans equalised.
Sounders was reduced to 10 men in the 55th minute when Lamar Neagle was shown a straight red card.
But two goals in six minutes from Michael Fucito gave Seattle a 3-1 lead before Comunicaciones defender Edgar Martinez was sent off 10 minutes from time.
An own goal from Rigoberto Gomez three minutes frm the end completed the scoring.
