Bottle Service (Season 2)

Bottle Service (Season 2) is an achievement earned for hitting an angry spectator in the head with an Expired Blackout Brew before the release of Patch 7.0.3.

Strategy
To earn this achievement, you must first talk to or  and purchase Expired Blackout Brew. After doing so, you may have a bit of a wait on your hands, depending on whether RNG favors you and whether other people around you are working on the same achievement.

Occasionally, one of the NPC spectators will get angry, begin yelling, and turn hostile. At this time, you must throw your bottle at him in order to earn the achievement. Be aware that the bottle has a 30 second cooldown, so aim carefully. Also, if you get too close to him, he will attack you, and you will need to stun or incapacitate him momentarily, as the throw mechanism on the bottle has a minimum range. It appeared that only one person can do this per hostile NPC (using the bottle on him turns him back to friendly), so you need to be pretty quick.