Serena is next test for Barna

German qualifier Anca Barna set up a match with top seed Serena Williams after defeating Belgium's Elke Clijsters in the first round of the Sparkassen Cup in Leipzig, Germany.

Barna beat the younger sister of top 10 ranked Kim Clijsters, 6-4, 6-3.
The German played the world No 1 at the US Open two years ago and won a set.

"Maybe Serena will have adjustment problems on this surface. I've already played four matches - plus she doesn't like my slice serve," said Barna, who reached the final at Estoril this year.