Williams, 23, had been jailed since he was convicted in July of groping two women and reaching inside their pants without their consent at a party in December 2010.
He maintained he was the victim of misidentification — several of the 80 people at the party were wearing Oklahoma State University warm-up clothes — and his supporters claimed he was a victim of racial bias.
Williams is black; his accusers are white. The jury in predominantly white Payne County included 11 white people and one of Asian descent.
Williams enrolled at OSU after his brother was shot to death on Chicago's South Side in 2009. His family had hoped the move would keep him out of danger, and Williams made the most of his time, leading the Cowboys in rebounding and averaging more than 7 points a game in 2010.
Coach Travis Ford suspended Williams from the team in February 2011 but testified as his trial that he believed he was innocent. Ford and several players attended the sentencing but did not speak to reporters.
Ford, who sat expressionless during the hearing, didn't immediately return a message left afterward seeking comment.
A network of supporters sprang up on websites and Facebook pages while Williams was in jail awaiting sentencing. Some packed the courtroom Friday, wearing black T-shirts that said "Free Darrell 25" — a reference to his uniform number.
Security was tight, with nine uniformed deputies on hand to keep order. Many people burst into tears when District Judge Phillip Corley denied Williams' request for a new trial and issued the suspended sentence. While Williams won't spend time in prison, he still has a felony conviction.
"Yes, he's out and he's free and that's great, but he has to register as a sex offender," friend Brandi Robertson said as Williams' supporters gathered outside the courthouse to await his release. "So my heart is broken for him. He's a good person and was done wrong and I'm very upset about it."
Williams was stoic during the sentencing and left the jail in a car that pulled out from a garage and drove off without stopping for him to talk to reporters. His mother, who was at the hearing, ignored a reporter's request for comment.
Defence attorney Cheryl Ramsey said she was "very upset" as she had expected Corley to order a new trial based on new evidence. She said she would appeal so Williams would have a shot at clearing his name.
"We thought that we had proven that the new trial motion should be granted," she said. Corley has ordered the new evidence sealed, and Ramsey has not said what it is.
Online court records show that the mental health and counselling records of at least one of the women have been subpoenaed.
Assistant District Attorney Jill Ochs-Tontz said that while prosecutors had hoped for more time behind bars, they were "thrilled" Williams would be forced to register as a sex offender and have a felony conviction.
"I hope that sexual assault victims across the state will see and know that no one is above the law," she said. "I honestly feel that Darrell Williams feels that he is above the law."
With no physical evidence in the case, Williams was convicted largely on the women's testimony, although Ochs-Tontz noted that one witness testified she saw Williams pull one of the victims to the ground at the party.
Williams' attorney, Cheryl Ramsey, characterized the case during the trial as a "he said, she said situation." She noted neither woman suffered cuts or scratches or had torn clothing. Defence attorneys also said Williams passed two lie-detector tests conducted by a State Bureau of Investigation examiner, though they were not admitted into evidence.
The women did not identify Williams as their attacker until three days after the party, when they were shown a photo of the basketball team by Stillwater police. Before that, the women wrote an anonymous letter to police and some media outlets outlining what happened.
At trial, one said Williams held her against her will and dragged her in a yard. She said the attack happened in the basement of the house and that no one came to her aid.
"I don't know what happened in the basement," Williams told police in a recorded interview played at his trial. "I was probably misidentified."
When the judge asked him if he had any comment before his sentencing, Williams continued to insist his conviction was a mistake.
"I'm innocent," he said. "I didn't do it."
His accusers did not attend the sentencing, although members of their families did, according to Ochs-Tontz. One victim told The Associated Press in August that the women had nothing to gain with their complaint.
"That's ignorance for people to say this is a race thing," she said. "It's not about race; it's about rape. He raped two girls."
The AP typically does not identify victims of sexual assault.