The woman reportedly invited the man to her hotel room at the Clarion Anaheim after meeting him on the internet.
The man jumped on the woman when she opened the door and raped her, police say.
In an effort to escape her attacker, the woman said she jumped from a second floor balcony.
The partially clad woman ran to the hotel lobby and told employees to call police.
The man was gone by the time police arrived.
He is described as a 24- to 26-year-old African-American man, about 5-foot-7 to 6-feet tall, weighing around 175 pounds with pulled back dreadlocks.
Investigators said looking at surveillance video in hopes of identifying the man.
The woman was taken to the hospital in stable condition.