ETOBICOKE, Ontario &ndash; The unbeaten Roxy Gap will get her sternest test to date Saturday at Woodbine in the $250,000 Natalma Stakes, a one-mile grass event for 2-year-old fillies. As part of the Breeders&rsquo; Cup Challenge Series Win and You&rsquo;re In program, the winner of the Grade 3 race receives an automatic berth into the BC Juvenile Fillies Turf Nov. 5 at Churchill.\r\nRoxy Gap won her debut with authority on the Polytrack July 3, and then doubled up in the restricted Shady Well Stakes, while earning her second straight 84 Beyer Speed Figure.\r\nRoxy Gap won the allowance prep for the Natalma in another romp, this time with an 89 Beyer. Trainer Mark Casse said he felt confident when he moved the daughter of Indian Charlie over to the turf for the one-mile prep.\r\n&ldquo;I find some of the Indian Charlies like the turf, and the dam had won on it,&rdquo; said Casse. &ldquo;I think she may just be a pretty good horse. Our turf course is a little different than others, and I think more Polytrack horses can adapt to it.&rdquo;\r\nCasse said Roxy Gap has some similarities to Sealy Hill and Tasty Temptation, the two best fillies that he has trained in recent years.\r\n&ldquo;She&rsquo;s like them in that you can work them with anybody, and they&rsquo;ll just stay head-and-head,&rdquo; Casse explained. &ldquo;She won&rsquo;t [draw off] and impress you, but when she runs, she runs fast.&rdquo;\r\nAmerican shippers Dos Lunas, More Than Real, and Street Chimes are in the nine-horse field.\r\nDos Lunas drilled the boys when she won her first start by six lengths, in a five-furlong turf dash at Churchill in June. After spinning her wheels in the slop at Saratoga in the Grade 3 Schuylerville Stakes, she wound up second as the favorite in the one-mile Junior Champion Stakes at Monmouth.\r\nDos Lunas was based at Saratoga before owner-trainer John Glenney worked her a half-mile in :49.20 here on the Polytrack last Sunday.\r\nMore Than Real recently changed trainers, going from Chad Brown to Todd Pletcher. She was victorious in her lone start in 1 1/16-mile maiden special on the turf at Saratoga, registering an 80 Beyer.\r\nStreet Chimes graduated in her only outing in a seven-furlong maiden special at Saratoga, which was taken off the turf and run over a sloppy main track. She is also trained by Pletcher, who has won four of seven starts in stakes at Woodbine this year.