England star Danny Cipriani had "glazed" eyes and his breath smelt of alcohol after he crashed his Mercedes car into a taxi, a court has heard.
The car was travelling "very fast" and "swerving and swinging" between the left and right-hand sides of the road, and hit a silver Toyota Prius which had slowed down to try to avoid it, it is alleged.
Cipriani accused the taxi driver of hitting his car, but he had been drinking, could not stand up straight and was "stuttering" and could not speak properly, London's Westminster Magistrates' Court heard.
The taxi driver, Muhammad Qasim, said he suffered injuries to his neck, shoulder and lower back in the crash on Imperial Road in Fulham, west London, at 5.15am on June 1 last year.
Sale Sharks player Cipriani, who has agreed a move to Wasps at the end of the season, denies drink-driving.
Katie Weiss, prosecuting, said police were called to reports of a traffic collision and found the taxi driver.
She told the court: "He said he picked up a passenger and was driving down the road. He saw a vehicle pull into Imperial Road which sped towards him.
"It began to swerve in the road and it entered the side of the road that Mr Qasim was driving on, resulting in the collision."
She said Pc Shane Elsworth questioned Cipriani, who allegedly admitted he had been out drinking.
She added: "Questions were put to the defendant. He said he was the driver of the vehicle. Pc Elsworth said he could smell alcohol on his breath and said his eyes were also glazed over.
"He was asked if he had been drinking and he said 'Yes'. He was asked, 'When was your last drink?'. He said, 'An hour ago'."
Cipriani, from Raynes Park in south-west London, was breathalysed and found to have 67 micrograms of alcohol in 100ml of breath, it is alleged. The legal limit in England and Wales is 35 micrograms.
The 28-year-old wore a navy suit and open-collared white shirt and spoke only to confirm his name, age and address at the beginning of the hearing.