Beckham came in for Juninho in the 70th minute and received loud cheers, his entry bringing some fans at the Galaxy's Home Depot Center ground to their feet.
The injury kept Beckham, England's most-capped outfield player, from playing in his fourth World Cup as he missed the 2010 finals in South Africa.
"Being out there felt good," Beckham said. "I've never been out of the game for such a long time."
Doctors had originally estimated Beckham would be ready to return in October, and he was pleased to get back to action sooner.
"It has been a quick recovery and I'm happy with that. I thought I was ready for 90 minutes four months ago," Beckham said.
Galaxy coach Bruce Arena said he was impressed with Beckham's determined rehabilitation.
"It's kind of remarkable that he's back on the field in such a short period of time," Arena said. "To put the kind of effort in to come back at his age is inspiring for our players to see.
"By the end of the season, we want him playing 90 minutes."
Four minutes after he came into the match, Beckham received a yellow card for a reckless foul against Emmanuel Ekpo.
But Beckham admitted he was feeling his lack of matches.
"After 10 minutes on the field, I thought like I was dying, Beckham said. "But I came through it, felt good after that and finished strong."
Buddle opened the scoring in the 13th minute, his first goal since August 14 and his league-leading 14th of the season. Kovalenko made it 2-0 in the 35th minute with his first goal in two years and Kirovski made it 3-0 in the 55th.
Mendoza scored for the Crew in the 85th.
Source: AFP American Edition