Salt Lake has managed just one win from its last five matches, going 1-4 in that stretch. But Alvaro Saborio's 11th minute winner secured RSL's second win since the All-Star break as the club closes in on fourth place in the Western Conference.
Saborio took advantage of some lackadaisical defensive ball movement when a back-pass escaped Chivas defender David Junior Lopes. The Real Salt Lake striker stripped Lopes of the ball before slipping past goalkeeper Dan Kennedy and slotting his shot into the open net.
Chivas had the potential to get back into the game when Real Salt Lake had a player sent off in the 24th minute.
Nick LaBrocca found himself through on goal but was tugged back by Nat Borchers, who was promptly shown a red card for denying a goal-scoring opportunity.
Chivas failed to take advantage of the sending off, as they could not get on the score sheet.
The win gives Real Salt Lake 39 points from its 24 games this season, enough for fifth place in the West. It trails the Colorado Rapids who occupy fourth with 41 points from 28 matches.
Chivas USA's second consecutive loss keeps it in seventh place in the West with 31 points from 27 games.
Real Salt Lake (11-7-6) returns to MLS action on September 3 when it hosts the Philadelphia Union, while Chivas (7-10-10) will remain home to face D.C. United at The Home Depot Center on September 10.