Engineer Will Williams decided to liven up a recent stag do by apparently downing an entire bottle of Jack Daniel's.
Williams, from Caernarfon, north Wales, allegedly carried out the dangerous stunt while at a service station in Chester at the weekend.
In the video, the 27-year-old appears to drink the entire bottle in around 15 seconds.
Speaking to The Sun, Williams said: “I was fine, for about an hour.
"I was pretty much instantly hammered. I carried on and stayed out until 3am the following morning. My mates were astonished.”
Jackie Ballard, the chief executive of Alcohol Concern, warned, “We need to remember that alcohol is a poison and can have extremely serious and immediate effects if consumed in a large amount at once."
Williams, however, seems unrepentant, and has been sharing secrets with his Twitter followers about how he managed to consume the alcohol so quickly.