Mark Casse has handled plenty of stellar turf fillies, including champions Tepin, a two-time Eclipse Award heroine, and Canadian Horse of the Year Catch a Glimpse. Nitrogen might not be at that level yet, but Casse said she is “catching up.” She remained unbeaten in four starts this year with a victory in the Grade 2 Edgewood for 3-year-old turf fillies on Friday at Churchill Downs, and will now eye an elusive Grade 1 win.