Ryan Garcia clearly wasn't sweating his flunked drug test in the hours before it became known to the public ... 'cause TMZ Sports has obtained video of him partying hard at an L.A. hotspot on Tuesday night -- seemingly without a care in the world.
Garcia hit up Bootsy Bellows in West Hollywood at around midnight -- roughly 20 hours before it was revealed he had Ostarine in his system the day before his huge upset win over Devin Haney -- and he danced at his table with no signs of worry.