 U.S. European Command said it would not comment on exactly why the measure was taken. Jay O'Brien, ABC News, Washington. Coco Gauff, who won the U.S. Open last September, closed out day one action on center court with a decisive victory over fellow American Caroline Delahaye. Last year I lost the first round here. It was a very tough moment for me. So I'm a little bit emotional just because it's been a long year. But it's incredible how I was able to turn it around.