The majority of the contest was closely-fought but Spain's Dominguez Lino came good in the deciding set as Robson's second serve crumbled.
Eighth seed Robson, who reached a career-high ranking of 39 on Monday, was facing an opponent ranked 20 places below her, although Dominguez Lino was playing on her preferred clay surface.
Elsewhere at the Polish tournament, third seed Klara Zakopalova progressed to the second round of the BNP Paribas Katowice Open after a 7-6 (7-2) 6-2 victory over fellow Czech Kristyna Pliskova.
Kristyna Pliskova's twin sister Karolina enjoyed a better say as she recorded a 6-1 3-6 6-0 win against Maria Teresa Torro of Spain.
Home hope Marta Domachowska could not progress beyond the opening round as she was beaten 6-3 7-5 by Annika Beck.