According to El Segundo police, the attacker grabbed the woman and forced her to the ground, then assaulted her through her clothing.
The victim was able to defend herself by warding off the suspect with pepper spray.
The assailant is described as a white male, about 30, weighing 200 pounds, and standing 6 feet tall. He has brown eyes and dark brown hair that is short on the sides and parted on the top.
He has a goatee with a weathered complexion , a muscular build with a large stomach and was last seen wearing a gray t-shirt and blue jeans.
Anyone with information on the attack or the suspect is urged to call El Segundo police Det. Ken Mulroney at (310) 524-2200.