Safina beat Japan's Shinobu Asagoe 6-2, 6-2, while Shaughnessy upset Frenchwoman Marion Bartoli 6-0, 7-5 at Amelia Island Plantation.
Other Day-1 upsets included Spanish qualifier Virginia Ruano Pascual beating 10th-seeded Frenchwoman Nathalie Dechy 7-6 (7-2), 6-4 and Ukrainian Alona Bondarenko beating 13th-seeded Argentine Gisela Dulko 6-0, 6-1.
Two other seeds avoided upsets, as No. 11 Anabel Medina Garrigues defeated fellow Spaniard Lourdes Dominguez Lino 6-3, 2-6, 7-5 and 15th-seeded Czech Lucie Safarova defeated Dutchwoman Michaella Krajicek 7-5, 6-7 (2-7), 6-4.
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