knock off one's feet

knock off one's feet  {v. phr.}

Удивлять (поражать) (кого-л.) до такой степени, что тот не знает что и делать.

Her husband's death knocked Mrs. Jones off her feet.

When Charlie was given the prize, it knocked him off his feet for a few minutes.

Ср.:

BOWL OVER (2),

SWEEP OFF ONE'S FEET.