Ash Barty has become a casualty at the WTA's Charleston Open, going out in the quarter-finals to the unseeded Paula Badosa

The world number one dropped her serve five times in the 6-4 6-3 defeat.

The Australian was the last remaining of the top eight seeds at the opening clay-court event on the WTA calendar

With the score at 3-all in the second set, Badosa broke Barty's serve twice including in the final game of the match.