破天荒

yī jiàn pò tiān huāng de dà shì

一件破天荒的大事

an epoch-making event

tā xiàng lái hěn shǒu shí jīn tiān què pò tiān huāng de chí dào le

她向来很守时，今天却破天荒地迟到了。

She had always been a punctual person, but exceptionally, she was late today.

pò tiān huāng dì yī cì

破天荒第一次

for the first time ever

tā wèi wǒ zuò le yī dùn fàn zhè duì tā lái shuō suàn de shang pò tiān huāng le

他为我做了一顿饭，这对他来说算得上破天荒了。

He cooked me a meal, which was a first for him.