The blaze, at a two-story, 1,500- square-foot San Clemente condominium in the 150 block of Avenida Baja, was reported just after 9 p.m., Orange County Fire Authority Capt. Steve Concialdi said.
The unit sustained extensive damage, about $150,000 in all, Concialdi said.
"A mom, a dad and a 2-year-old child were inside when the fire started in a bedroom, but the occupants got out," Concialdi said.
No injuries were reported, he said.
Thirty firefighters had the fire under control in about a half hour, Concialdi said.
City News Service contributed to this report.