The blaze broke out Sunday afternoon near the 39000 block of via Temprano. Winds fanned the flames, which burned about 200 acres.
The fire is about 90 percent contained. It had been reduced mainly to embers but still posed a potential threat if afternoon winds pushed it over fire lines, Murrieta Fire Chief Matt Shobert said.
At one point, the fire threatened as many as 200 homes in the Los Alamos Hills neighborhood. At least one outbuilding and an RV were damaged.
The cause of the blaze remains under investigation.