World number four Victoria Azarenka has said that she is pleased with her first performance at the WTA Championships in Istanbul.

The 22-year-old got her White Group campaign off to a winning start this afternoon with a straight-sets win over US Open champion Sam Stosur.

After the match, Azarenka confessed that she was a little surprised by the quality of her display.

"I feel great. I wasn't expecting to play so well in my first match here," Azarenka said during her on-court interview. "It was getting close in the end, we had a really close last game. Sam started to really go for every shot with nothing to lose, and I backed up a little bit.

"She made some incredible shots. But I stayed strong. I had to work for it. I'm glad I finished it when I did.

"I served very well today and I wish I can continue to play like this."

Azarenka has now won six matches in a row.