The Mexican attacker came on in the second half for his first minutes with the MLS club and scored in his debut.
Mexican international Giovani dos Santos made his LA Galaxy debut in the 57th minute of the club's CONCACAF Champions League match against Central FC and scored just 19 minutes later, making his debut.
The attacker replaced Alan Gordon with the scoreline at 3-1 after Gordon's early goal, a questionable penalty converted by Central's Atualla Guerra, and goals from Raul Mendiola and Gyasi Zardes, who also scored from the spot.
Dos Santos used his left foot to guide in a cross from Rafael Garcia, who had been sprung down the left side of the box by Sebastian Lletget.
The Galaxy added another goal to take a 5-1 triumph in their first match of 2015-16 CONCACAF Champions League play.
The 26-year-old Dos Santos previously played for Villarreal and joined the Galaxy during the summer's Gold Cup. The Galaxy's next match is Sunday when they host the Seattle Sounders in league play.