World number four Coco Gauff was undone by 14 double faults and 54 unforced errors as she fell to a surprise singles defeat – but recovered in the doubles to help the United States beat Spain to reach the quarter-finals.
Gauff lost 6-1 6-7 (3-7) 6-0 to 42nd-ranked Jessica Bouzas Maneiro as the two-time major champion’s nine-match unbeaten streak in the United Cup – winning six singles matches and all three of her doubles contests – came to an end.
A first top-five victory for Bouzas Maneiro gave Spain a 1-0 lead before Taylor Fritz levelled the tie after saving a match point against Jaume Munar in the men’s singles match.
Gauff returned alongside Christian Harrison for the mixed doubles, beating Inigo Cervantes and Yvonne Cavalle 7-6 (7-5) 6-0 to ensure the defending champions topped Group A.
In Group F, world number three Alexander Zverev suffered a surprise defeat as Germany were beaten by Poland.
Zverev lost 6-3 6-4 to former top-10 player Hubert Hurkacz, who was playing his first competitive match since June.
Hurkacz, who has dropped to 83rd in the rankings since suffering a knee injury seven months ago, triumphed to give Poland a 1-0 lead in Sydney.
Six-time major champion Iga Swiatek secured victory for Poland, although she had to fight back from a set down to avoid a shock defeat against Eva Lys.
Lys had never won a set in her three previous encounters against the world number two, but could not sustain her level in a 3-6 6-3 6-4 defeat.
