自欺欺人

zì qī qī rén

to fool yourself as well as others

Character by character

自zì
self

欺qī
deceive

人rén
others

明明输了还说自己赢了，这不是自欺欺人吗？

Plainly beaten yet claiming to have won: is that not fooling yourself and everyone else?

Tone: negative (criticism).

Learn this in Lesson 210 · HSK 9+: 鲁迅与白话文 (Lu Xun and the birth of modern writing)

A dialogue, a reading, word cards with audio and a drill that uses it, in Learn Chinese with Bao. The first lessons of every level are free.