The coffee shop helper thought she was being helpful by pointing out where the toilet was to a patron.
But the patron could not find the toilet and he threatened her instead.
When the coffee shop's regulars came to her defence, all hell broke loose as a brawl erupted with chairs and beer bottles being thrown.
A video of the fight was posted on citizen journalism website Stomp.
The fight happened late last Saturday night at the coffee shop at Block 546, Jurong West Street 42.
It all started when a patron, who was drinking with two of his friends, asked coffee shop helper Qiu Chang Jin, where the toilet was.
Ms Qiu, 40, told The New Paper: "I told him where it was but he came back shortly, telling me he could not find it.
"I was terrified when he started to scold me for lying and even threatened to beat me up. I was thinking, I came here from China to Singapore to work, too, so what did I do wrong?"
"The regulars there were very concerned over what happened and assured me they will protect me if anything bad happens," said Ms Qiu, 40, a Chinese national who has been working as a coffee shop helper for over a year.