PERTH, Jan 5 — World number four Coco Gauff suffered her first-ever defeat at the United Cup on Monday when she was stunned by Spain’s Jessica Bouzas Maneiro 6-1, 6-7 (3/7), 6-0 in a blow to her Australian Open preparations.

Gauff had won all six of her previous United Cup singles matches for the USA and had a 3-0 record in mixed doubles.