Tiffany Ottley and Three Kings competing at the Horse of the Year show in Hastings.
Ottley (32) and her Clydesdale-cross gelding Three Kings also won best presented in the side-saddle class, which attracted entries from throughout New Zealand.
Ottley has been riding side-saddle for about 10 years and it was the highlight of the combination's career.
Her classroom at Waimate High School was decorated in celebratory fashion, with banners and balloons, by her pupils when she returned to school last week.
The Horse of the Year show attracted about 2600 horses and ponies, competing in 16 equestrian disciplines.
