bowl over

verb

1. informal.
   to surprise (a person) greatly, esp in a pleasant way; astound; amaze

   he was bowled over by our gift

2. to knock (a person or thing) down; cause to fall over

Idioms and Phrases

Astonish, surprise greatly, overwhelm, as in I was simply bowled over by their wonderful performance . This term originated in cricket, where it means “to knock all the bails off the wicket.” [Mid-1800s]