Real Salt Lake's first-half lead was short lived.
After RSL midfielder Khari Stephenson broke the deadlock with a 44th-minute goal, L.A.'s Landon Donovan answered right back.
A ball took a bounce off RSL defender Nat Borchers and fell right to Donovan, who smashed a shot to beat Salt Lake goalkeeper Nick Rimando.
Stephenson's goal, his first MLS score of the year, seemed to be coming throughout the first half. Stephenson ripped a shot from distance just high over the crossbar in the 22nd minute. Four minutes later, Stephenson pinged the post on a free kick from 30 yards out.
Stephenson finally broke through after taking a pass from forward Robbie Findley, and driving a low show past Galaxy goalie Brian Rowe.
Los Angeles forward Jose Villarreal provided a pair of quality chances for the visitors, smashing the crossbar with a shot and later putting a free kick on frame only to see Rimando punch it away.