Top seed and former champion Sloane Stephens crashed out of the Citi Open in Washington today.

The 2017 us open champion suffered a stunning 6-2 7-5 first-round loss to swede Rebecca Peterson.

Up next for Peterson will be the winner of a Tuesday clash between American Sachia Vickery and Italian Camila Giorgi.

Olympic champion Monica Puig also advanced with a 6-4 6-2 victory over American allie kiick and will face Russian Anna Kalinskaya in the second round.