DOHA, Qatar -- Australian Open champion Angelique Kerber made a disappointing return to tournament tennis on Tuesday, losing 7-5, 6-1 to China's Zheng Saisai in the second round at the Qatar Open.
Kerber beat Serena Williams at Melbourne in the opening Grand Slam of the year on Jan. 30. The top-seeded Kerber split two matches in Germany's loss to Switzerland in the Fed Cup and received a first-round bye at Doha.
Zheng, ranked 73rd, made just eight unforced errors compared to 38 by Kerber and needed only 28 minutes to win the second set.
"The feeling is amazing," Zheng said. "For sure it wasn't her [Kerber's] best tennis today, but I'm happy I won that match."
Kerber, who withdrew from last week's Dubai Open with a right thigh injury, said, "I was not feeling good from the beginning."
"I think you have days like this sometimes," Kerber said. "I don't know how many mistakes I did today. This is not my game ... that's all I can say."