Serena Beat Venus to reach semis of US Open 2008

Stubborn Serena Williams refused to roll over Wednesday against her big sister Venus, saving 10 set points in a heroic struggle before pounding out a 7-6 (8-6), 7-6 (9-7) win to advance to the semi-finals of the US Open.

The fourth seed, who lost to her sibling in the Wimbledon final, made sure that scenario did not repeat itself with an intense victory in well over two hours.

Serena Williams, now 9-8 in the series with her sister, reached the final four in New York for the first time since 2002 when she won the title over her nearest relative.

Safina maintained her impressive form as she swept past Italy's Flavia Pennetta 6-2 6-3 to reach the semi-finals of for the first time.

The Russian, who has made the final in six of her last seven tournaments, broke the 16th seed at the first attempt and overpowered her in the first set.

Pennetta put up a better fight at the start of the second but lost her way and Safina sealed a comfortable win.

Safina, the sister of 2000 champion Marat Safin, had never previously been past the quarter-finals at Flushing Meadows, and the French Open runner-up said: "I'm getting closer to reaching the same thing as my brother."

Olympic champion and fifth seed Elena Dementieva faces second seed Jelena Jankovic in the other semi-final.