People from more than 60 countries took part in the online poll for the award, the brainchild of Penny Chenery, the owner of 1973 Triple Crown winner Secretariat.
Peter Tighe, Debbie Kepitis and members of Richard Treweeke's family travelled to the United States for the occasion on Saturday (Sunday AEDT).
Tighe told Sky Sports Radio the American fans had embraced them and Winx.
“We are honoured to accept the award on behalf of Winx,” Tighe said.
“We have been sitting signing posters for an hour. The club had them made up and gave them to the patrons.
“There were hundreds of people lined up for us to arrive this morning.
“Everyone has thanked us for coming and thanked us for Winx and what she has brought to racing.”
“For a horse from out of America to win an award here, it's very special and it's not lost on us,” Kepitis told American racing broadcaster TVG.
“She's an amazing equine athlete and we are just fortunate to be watching and to be part of this phenomenal magic carpet.”