The incident happened around 5 a.m. at the Clarion Hotel Anaheim Resort at 616 W. Convention Way.
Investigators said the woman and man had previously been communicating on the Internet and were meeting for the first time.
"They had chatted on the Internet, decided they were going to meet at this particular location," said Sgt. Bob Dunn of the Anaheim Police Department. "During that encounter, (the situation) somehow turned violent and the female wanted to escape. Her only way of escape was to jump off that second-story balcony."
The woman survived the jump. Police said the partially clothed woman went to the hotel lobby to report the alleged assault.
The woman was at the hospital to treat injuries sustained during the attack and from the fall. She was in stable condition.
Officers were unable to find the suspect. He was 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 they were going to look at surveillance video.
Anyone with information on the case was asked to call Orange County Crime Stoppers at (855) 847-6227.