In her first race going long around two turns, Brereton Jones’ Canadian Mistress scored an impressive maiden victory at Delaware Park today.  With Gabriel Saez astride, the 3-year-old daughter of Canadian Frontier won by 21 ½-lengths and covered the mile-and-seventy-yards in 1:41.84 over a fast main track.  The Kentucky-bred conditioned by J. Larry Jones returned $3.20 as the favorite in the field of six.  She sports a career record of a win and two seconds from four starts with earnings of $42,600.