Burnley magistrates heard how Mohamed Afzal was stopped on a routine check by officers.
They believed the 22-year-old was under the influence of something. The defendant's breath smelled of alcohol, his eyes were glazed and his speech was slurred.
Afzal gave a positive roadside breath test, showing 51 microgrammes of alcohol in 100 millilitres of breath. The legal limit is 35.
Miss Parveen Akhtar, prosecuting, said at the police station, the defendant gave breath samples, but not enough to provide readings.
Mr David Leach, defending, told the hearing Afzal had had a shot of vodka. He thought it was a double shot.
He was parked on a garage forecourt with friends when police approached him and smelled alcohol on his breath.
The defendant did provide two police station samples, giving readings of 48 and then the lower reading of 44 microgrammes.
"But it's not one that is admissible for court," said Mr Leach.
The solicitor added: "He wasn't being evasive. It was just simply naivety."
The defendant, of Thursby Road, Burnley, admitted falling to provide a specimen for analysis on September 24th.
He was fined Â£150 and was told to pay a Â£30 victim surcharge and Â£85 costs.