Wǒ zhèng yào jièshào fāng'àn, tā yí jù huà jiù chāitái le.
I was about to pitch the plan — one line from him and it fell apart.
Tips
history
Xinhua词典 defines it as 'destructive tactics to topple a person/group or derail an effort'. The image is theatrical — literally dismantling the stage mid-performance, so the other actor crashes. Preserved in Peking opera jargon before becoming everyday vocab.
usage
Antonym: 捧场 (to show support / be a good audience). A classic pair in office politics — one 捧场 partner makes you look good, one 拆台 rival makes you look foolish.