New York - Serena Williams stormed into the semi-finals of the US Open on Wednesday with a 6-1, 6-3 demolition of Serbia's Ana Ivanovic.

The last American left in the tournament after Andy Roddick was sent into retirement by Juan Martin del Potro, Williams was at her irresistible best as she steamrolled Ivanovic in less than an hour.

Williams, chasing her fourth US Open title and her 15th grand slam, plays Italian Sera Errani in Friday's semi-finals with the winner to face either Maria Sharapova or Victoria Azarenka in the final.

“I think I came out really strong,” Williams said in a courtside interview. “Playing against someone like Ana, a former world number one, you really have to play amazing tennis.” - Reuters