Williams, 32, pleaded not guilty to the charge last November and his trial is taking place at Wolverhampton Crown Court.
Williams, from Croydon, was arrested in December 2016 following allegations he had attacked a woman at a hotel.
He stands with co-defendant Jamien Nagadhana, his tour manager, also 32, from Hounslow in west London.
Mr Nagadhana denies a charge of assault by penetration in connection with the same incident.
On the first day of the trial, a jury of eight women and four men was sworn in, and asked if they knew either defendant or any of the 14 witnesses personally.
Opening the Crown’s case, prosecutor Miranda Moore QC alleged that Williams raped a “zombified” woman who went to his hotel room to look for her mobile phone.
Prosecutors allege that the rape took place in December 2016 after the woman and two of her friends had met Williams and his tour manager Mr Nagadhana at a Wolverhampton nightclub following a solo gig.
After one of the women “blacked out” and had to be put in a taxi home, the alleged rape victim and her other friend went back to the hotel with Williams and Mr Nagadhana, the court heard.
Ms Moore told jurors: “All three of the women began to feel a lot more affected by alcohol than they felt was normal. They all began to feel odd.”
Adding that one of the women felt she had been drugged, Ms Moore told the court: “That was her feeling but there is no forensic evidence to support that.”
The prosecution claims Williams had previously attempted to have sex with the woman, but she had made it clear she did not want to have sex and left his room.
Describing how the woman went back without her friend to look for her mobile, Ms Moore said: “Once she was back in the room – she had to knock on the door – Mr Williams effectively jumped on her.
“He picked her up and pushed her down on the double bed. She had already made it clear that she didn’t want to have sex with him.
“All she thought was ‘I don’t want this to happen’.”
The complainant told police that she had sworn at Williams during the alleged rape and told him to get off her – but felt she had not been “as ‘fighty’ as she should have been”.
After his arrest, the court heard, Williams was interviewed by police and told them the alleged victim and her friend had wanted to go back to the hotel and had instigated sexual activity.
There had been a “free-flowing vibe” at the nightclub, Williams told officers, and he was “getting on well” with the alleged victim.
During his account, Williams told police: “I’m the artist. I think both of them, they both kind of wanted to be involved with me in some degree.”
The woman claims Mr Nagadhana – who she described as Williams’ “really weird friend” – sexually assaulted her during the alleged rape.
But Ms Moore told the jury Williams had told police Mr Nagadhana “had nothing to do with it at all” and was asleep.
Ms Moore said: “He (Williams) claimed she was fine with it – she didn’t say anything about stop or get off.”
In a video interview with police shortly after the incident, which was played to the jury, the complainant said: “The whole time I was telling him to stop and to f*** off.”
At one point during the alleged rape, the woman, who cannot be identified, said she had “laid down like a dead body” because she just wanted it to stop.
She told an interviewing police officer: “I was quite scared. I felt more pathetic, if that makes sense. I felt just worthless.”