Stephens loses in 1st round at Dubai Championship, latest setback since Australian Open run

Jie Zheng of China returns the ball to Russia's Ekaterina Bychkova during the first day of Dubai Duty Free Tennis Championships in Dubai, United Arab Emirates, Monday, Feb. 18, 2013. (AP Photo/Kamran Jebreili) (The Associated Press)

Karla Zakopalova of Czech Republic returns the ball to Marion Bartoli of France during the first day of the Dubai Duty Free Tennis Championships in Dubai, United Arab Emirates, Monday, Feb. 18, 2013. (AP Photo/Kamran Jebreili) (The Associated Press)

Sloane Stephens lost in the first round of the Dubai Championship on Monday, the latest setback for the American rising star who reached the Australian Open semifinals.

Stephens, who has risen to 16 in the world rankings after knocking out Serena Williams in Melbourne, lost to Sorana Cirstea of Romania 5-7, 6-3, 6-2.

Last week, Stephens lost to Klara Zakopalova in the third round of the Qatar Open.