Duque-Colsanitas posted a 4-6, 7-5, 6-1 decision over the Luxembourg native, winning 42 percent of her second-serve points while taking advantage three Minella double faults in the final set.
She goes on to face sixth-seeded Ukrainian Elina Svitolina, who used a pair of tiebreakers to dispatch American Julie Cohen 7-6 (7-2), 7-6 (7-5) to reach the quarters.
No. 4 seed Alexandra Panova of Russia rallied past Canadian Eugenie Bouchard 3-6, 7-5, 7-6 (7-4) and Paula Ormaechea of Argentina made the quarters as well, outlasting Spain's Estrella Cabeza Candela 6-7 (8-10), 6-2, 6-1.
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