Alan Paul Wurtzel, 67, of Pacific Palisades, entered the plea Wednesday before Superior Court Judge Barbara Johnson.
Wurtzel met 53-year-old TV executive Carole Markin on the dating website in early 2010 and went on two dates. On the second date, Wurtzel drove Markin home, followed her into her residence and allegedly sexually assaulted her while holding her down.
Attorneys for Wurtzel contend that a rape never took place and that the sex was consensual.
Markin, who revealed her identity on ABC's "Good Morning America" in April, has sued Match.com after the alleged rape. She called on the dating website to implement a sexual predator screening system.
Officials at Match.com heeded her demand, saying the company would begin cross-referencing members against the National Sex Offender Registry. They also said, however, that members need to take measures to protect themselves.
Wurtzel is due back in court for sentencing Sept. 19. If convicted, he faces one year in jail, five years of probation and he must register as a sex offender for life.