British number one Katie Boulter was knocked out of the US Open second round in a "horrendous" straight-set defeat by Spain's Jessica Bouzas Maneiro.
Boulter, the 31st seed, started strongly in the opening set, breaking first before Bouzas Maneiro found her footing.
The world number 74 stormed into the lead in the second set and held off a late surge to close out a 7-5 7-5 victory.
Boulter was heard saying "everything was horrendous" to her team at the side of the court.
The 28-year-old has leapt up the rankings after a strong 18 months, but she has yet to reach the second week of a Grand Slam.