The blaze was reported at about 3 p.m. near Gazos Creek Road, south of Pillar Point.
Firefighters responded with a number of crews and several aircraft, including a helicopter and two air tankers, Cal Fire Capt. Scott Green.
The fire, which burned along the east side of Highway 1, brought down power lines.
"We had to hold back a little bit because of the power line issue and firefighter safety," Green said.
The California Highway Patrol shut down the highway in both directions while firefighters battled the blaze. At 4:20 p.m., one lane was reopened and one-way traffic was being allowed through, CHP Officer John Short said.
Shortly before 5 p.m., firefighters had contained the blaze to about an acre and expected to have it controlled within two hours, Green said.