To throw somebody a curve ball - to surprise someone with something that is difficult or unpleasant to deal with. Example - "Mother Nature threw us a curve ball last winter with record-breaking amounts of snow."
To hedge one's bets - to protect yourself against loss by supporting more than one possible result or both sides in a competition. Example - "They're hedging their bets and keeping up contacts with both companies"
Faint of heart - people who are squeamish; someone who is sickened or disturbed by unpleasantness or challenge. Example - "The pathway around the top of the volcano, near the crater, is not for the faint of heart"
Beleaguered - having a lot of problems and difficulties; put in a very difficult situation. Example - "The arrival of the fresh medical supplies was a welcome sight for the beleaguered doctors working in the refugee campus"
You have got to hand it to somebody - expression used to refer to someone who has done something successfully. Example - "I mean, you have got to hand it to her. She's brought up three children on her own"