After two impressive men’s semifinal matches - who gets your vote for the #EmiratesAce of the Day - @rafaelnadal or @kandersonatp? Tag your favorite in the comments below and include #EmiratesAce for a chance to win tickets & other prizes! #USOpen #usopen2017 #aces #rafanadal #rafa #kevinanderson #instatennis #arthurashestadium