Britain's Heather Watson has been knocked out in the second round of the WTA Carlsbad tournament in San Diego by Taiwan's Chan Yung-Jan.
Watson, who recently reached a highest-ever ranking of 71st in the world, went down 3-6 6-7 to the world number 161.
The 20-year-old won her first WTA title last week with a victory in the women's doubles at Stanford.
Yung-Jan will face either Jelena Jankovic or Melinda Czink for a place in the fourth round.