Wozniacki, Williams set for semi

World No 1 will face 13-time Grand Slam winner in US Open clash

NEW YORK - Caroline Wozniacki is the world number one, but she goes into a heavyweight women's semi-final at the US Open on Saturday very much the challenger to three-time champion Serena Williams.

The final four match on Saturday night will have a championship flavor, but a defiant Wozniacki insists she doesn't need to pass any test posed by Williams to prove herself worthy of her top ranking.