6:02 AM PT -- 10/22 -- Oscar De La Hoya is firing back at the allegations -- claiming the lawsuit is bogus and calling himself a "prime target" for a false lawsuit.
"A frivolous lawsuit was filed recently alleging that Oscar De La Hoya sexually assaulted ‘Jane Doe,’ which is completely false," Oscar's rep said in a statement.
"Oscar is a very successful businessman, running one of the country’s leading sports and entertainment companies – thus a prime target. It is worth noting that both recent lawsuits have been filed by the same attorney who is looking to make a name for himself. We vehemently deny these allegations and look forward to vigorously defending Oscar’s good name and reputation."
Oscar De La Hoya is being sued by a woman who claims the boxing legend sexually assaulted and battered her during a booze-fueled 2017 hookup ... and the allegations are graphic.
The woman who filed the suit uses the alias "Jane Doe" to protect her identity -- but describes herself as a licensed vocational nurse who met Oscar in 2016.
In her suit, filed in L.A. County Superior Court, Doe admits the two had an ongoing consensual sexual relationship, but says things went awry in Nov. 2017 when he invited her over to check out his new house in Pasadena.
Doe claims Oscar had bottles of alcohol and "a bag of what appeared to be cocaine" in his kitchen when she arrived -- and she claims it became clear, he was on a mission to get wasted.
After Oscar became intoxicated, she claims the boxer invited her to the bedroom to hook up -- and during the encounter, he asked if she was down to "experiment" sexually.
Doe claims she declined various unusual requests and Oscar became frustrated -- but things came to a head when he "ultimately held her down with one arm while forcefully trying to insert his fist into Plaintiff's vagina."
In her suit, Doe claims she "repeatedly said no and demanded that De La Hoya stop. However, De La Hoya overpowered her and suddenly and forcefully pushed his hand and fist into Plaintiff's vagina."
Doe claims she screamed in pain and yelled at Oscar -- but he just laughed and told her to take a shot of alcohol. The woman claims she refused the booze and angrily left the house.
After the incident, Doe claims she "felt extreme swelling and pain for which she was prescribed medication at urgent care."
She also "sought treatment with a Doctor of Psychology and Certified Sex Therapist who diagnosed Plaintiff with Post-Traumatic Stress Disorder arising from the sexual battery by De La Hoya."
The woman does not say in her suit if she ever filed a report with police.
Doe claims she still suffers from extreme distress, humiliation, indignation and outrage -- along with depression, anxiety and related symptoms associated with post-traumatic stress disorder.
In her suit, filed by attorney Greg Kirakosian, Doe is demanding unspecified damages for sexual assault, sexual battery, gender violence, negligence and intentional infliction of emotional distress.
We reached out to multiple people in De La Hoya's camp multiple times -- so far, no word back.