Adrian Peterson Admitted To Boozing At Poker Game Hours Before DWI Arrest, Cops Say

Police in Sugar Land, Texas say Adrian Peterson fessed up to throwing back shots of a vodka mix at a poker game early Sunday morning ... just hours before he was arrested for DWI.

The officer who took Peterson into custody over the weekend wrote in court documents, obtained by TMZ Sports, that the former NFL running back made the admission while the two were at a Sugar Land gas station at around 9:23 AM.

The officer alleged in the docs he encountered Peterson asleep at the wheel of a running black Mercedes SUV that was next to some pumps ... and he claimed once he woke up the unconscious ex-Minnesota Vikings star, he reeked of booze and had blood shot, glossy eyes as well as a slurred speech.

The cop claimed Peterson told him he had been playing cards in Houston just before their encounter ... and stated he consumed "approximately 2 to 3 shots of a vodka mix" roughly "2 or 3 hours ago."

A witness who was at the poker game and photographed the football legend during one of the hands told us he saw Peterson "drinking like a fish." An additional witness said Peterson was at the game for hours, and went back and forth from the poker game to his car to pick up money to place more bets.

At the gas station, Peterson's arresting officer claimed he said "from a scale of 0 being completely sober to 10 being intoxicated to the point of blacking out ... Peterson stated he was a 2."

Peterson allegedly went on to bomb the field sobriety tests ... and once he was thrown into cuffs for DWI, the docs state a pistol was discovered inside the front passenger side glove box of his car.

Peterson was eventually hauled off to jail and booked on one count of DWI and one count of unlawful carrying of a weapon. Cops say they're still awaiting the results of his blood test.