I did once run across some nice phrases at the end of a karate book, which (judging by the lack of hiragana) had been lifted, unattributed, from a chengyu-style source.
If we take 4-word to be the equivalent of 4-character:
Parry? Wait 'til late
Your lunge surprises yourself
Champion with two techniques
(hmm, that worked better than I thought it might!)