surprise by

surprise (one) by (doing) (something)

To shock, amaze, or astonish one by doing, possessing, or demonstrating something. I must say, he surprised me by his honesty. I thought for sure he'd try to deny it or weasel his way out of a punishment. The kids surprised me by making me breakfast in bed for my birthday.
See also: by, surprise
Farlex Dictionary of Idioms.

surprise someone by something

to astonish someone by doing or being something. You surprised me by your forthrightness. No one was surprised by the way it happened.
See also: by, surprise
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • surprise (one) by (doing) (something)
  • surprise (one) with (something)
  • surprise with
  • take (one) aback
  • take aback
  • take someone aback
  • taken aback
  • set (one) aback
  • throw (one) for a loop
  • throw someone for a loop
References in periodicals archive
I would like to look at two homologous scenes to show the indirection of wish fulfillment in the novel--the mechanism of surprise by which Catherine is rewarded, and the rhetoric of probability and stoic resignation that surrounds each event.
Jane Austen's aesthetics and ethics of surprise
We are such control freaks that when we do desire a tiny little element of surprise in our lives we choose a little gambling experience or extreme sporting encounter knowing full well that we can end the element of surprise by walking away from the game.
Chock full of surprises: learning to embrace the grace of living out of control
There has been some recent evidence of renewed interest in the long-dormant telecommunications sector, instigated by a positive surprise by NTT, with its latest quarterly results.
The Bloom is off the boom, and the Yen also rises: our analyst sees the market dipping as currencies play power games