Singer Courtney Love will face trial later this month after a Los Angeles judge rejected a plea for evidence to be suppressed.
Courtney Love faces trial in Los Angeles on 16 April
The case against Love would have collapsed if evidence such as urine samples had been ruled out.
The widow of Nirvana's Kurt Cobain faces charges of disorderly conduct and being under the influence of drugs.
Love was arrested last October after damaging her ex-boyfriend's house in the middle of the night.
"This was a vital ruling," said prosecuting lawyer Jerry Baik. "It would have killed our case," he added.
Love, who was the frontwoman of rock band Hole and has recently released her solo debut album, was not present at the hearing.
When the 39-year-old appeared at an earlier hearing, she arrived two hours late and was asked to be silent after interrupting proceedings.
In a separate incident, she was charged with assault last month after allegedly injuring a man by throwing a microphone stand at him at a performance in New York.
The 24-year-old received hospital treatment for his wounds.
After her arrest last October, Love admitted to police that she had taken the painkiller Oxycontin - known as "hillbilly heroin".
Her defence lawyer Michael Rosenstein asserts that police were unaware that Love had taken the drug without prescription, and that a taxi was waiting to take her home.
The singer was separately charged for illegally possessing the painkilling drugs Oxycodone and Hydrocodone, which were found when she was later admitted to hospital.
Love broke a number of windows at her ex-boyfriend's house, but he declined to press charges for vandalism.
A date of 16 April has been set for the trial to start.