Catch him flat-footed - Idioms by The Free Dictionary
catch (someone) flat-footed (redirected from catch him flat-footed)
catch (someone) flat-footed
To startle someone; to come upon someone unawares and/or when he or she is unprepared. Usually used in the past tense. The security guard caught the thieves flat-footed. That essay question in the exam caught me completely flat-footed.
References in periodicals archive
So, to be beaten after 20 minutes by a long-range strike that appeared to catch him flat-footed
was not the best way for Foster to respond.
The muddling gallop and injection of pace early in the straight appeared to catch him flat-footed
before he hit top gear coming up the hill, staying on strongly to be beaten the narrowest margin by Shirley Casper.