The Mexican international who grew up in Los Angeles put a ball into the net far post off a give-and-go play with teammate Sacha Kljestan in the 53rd minute. Alvarez, who'd been with the Mexican national team in its run to the CONCACAF Gold Cup final but never appeared, gave his hometown team its 11th win in the past 12 meetings at home with Real Salt Lake.
LA had far more chances than the visitors from Utah, and had a goal from Kevin Cabral called off when Cabral was ruled offside in the first half. Samuel Grandsir had a chance for his second goal in as many matches, but his 25th-minute shot sailed over the goal.
The Galaxy had eight shots on goal and forced Real Salt Lake goalkeeper Zac MacMath into seven saves. Midfielder Sebastian Lletget, a few days removed from winning the Gold Cup with the U.S. national team, appeared as a substitute in the second half.
The Galaxy also missed plenty of opportunities to add to their lead. But they have their first set of back-to-back victories since June 23 and 26, when they got consecutive wins over Vancouver and San Jose.
Real Salt Lake had been on a three-game undefeated streak with two draws. They had shut out their past two opponents with a win and scoreless draw.