In [article id="1625556"]Rihanna's first sit-down[/article] since Chris Brown assaulted her in February, the pop star explained to Diane Sawyer what happened the night that the attack took place, confirming the rumor that it all began over an argument about a text message Brown had received.

"We had a blast that night," she said in the part of the interview that aired on "Good Morning America" Friday (November 6). She went on to describe how the fun night spent at a pre-Grammy party soon escalated into violence after she confronted him about a text message she found from an unknown woman on his phone.

"I caught him in a lie, and he wouldn't tell the truth," she said. "I couldn't take that he kept lying to me. And he couldn't take that I wouldn't drop it.

"He wouldn't tell the truth and I wouldn't drop it," she went on. "The truth is right here in text messages, so it escalated into him being violent towards me and ... it was ugly."

In the interview, which will air in full on "20/20" Friday night, [article id="1606362"]Rihanna confirmed the account in the police report[/article] that Brown was driving as he shoved Rihanna into the car window, punched her several times in the face, bit her and threatened to beat her up when they got home. When she tried to call his assistant for help, he told her she had made a huge mistake, threatened to kill her and threw her phone out of the window.

She tried to fend him off with her feet, but "it was not like a fight with each other. I just really wanted it to stop," she said. "All I kept thinking the whole time: When is it going to stop?

"He had no soul in his eyes, just blank," she added. "He was clearly blacked out. There was no person when I looked at him."

Someone who heard her screaming called 911, but initially she had no idea how she was going to get help. "I was battered. I was bleeding. I was swollen in my face," she said. "There was no way of me getting home. My next option was to get out of the car and start walking in a gown and a bloody face, so I really don't know what was my plan. I didn't have a plan; that whole night was not part of my plan."

Soon after, the police photo showing Rihanna's injuries leaked to the Web. "Who likes seeing their face like that? I feel humiliated. I get angry, all over again, every time I see it," she said. "The whole thing plays back in my head, so I don't like to see it."

When she looks back on that night, Rihanna said she isn't sure what made Brown's anger escalate to that point. "There's nothing you can do or say to make somebody do that to you," she said. "That's on them. I just knew he had a problem. He had a temper. He needed to get some help. And he did.

"The thing men don't realize when they hit a woman, it's the face, the broken arm, the black eye, it's going to heal. That's not the problem. It's the scar inside," she continued. "You flashback. You remember it all the time. It comes back to you, whether you like it or not. And it's painful, so I don't think he understood that. They never do."

Go [article id="1605165"]here for domestic-violence resources[/article], or check out Think MTV for a video handbook on spotting the warning signs of abuse.