Serena Williams looks right at home as she cruises into last four

Serena Williams in powerful mood against Ivanovic (AFP)

The pressures of playing in her home Grand Slam tournament have got to Serena Williams in the last two years but the Wimbledon champion is looking in good shape to claim her first US Open title since 2008.

Williams, who beat Ana Ivanovic 6-1, 6-3 in the quarter-finals here on Wednesday, has lost just 16 games in her first five matches, in which she has hit 41 aces.

When Ivanovic held serve for 3-1 in the first set it ended a run of 23 games in a row that Williams had won. "I didn't think I came into this tournament playing my best, but I definitely played better in the last two matches," Williams said. In today's semi-finals the American meets Sara Errani, the French Open runner-up. The 25-year-old Italian began the year ranked No 45 in the world but has climbed into the top 10 in the course of the best season of her career.

The other semi-final sees a heavyweight clash between Victoria Azarenka, the world No 1, and Maria Sharapova, who will reclaim the No 2 position next week.

Azarenka has won four of their last six meetings, but the records of both women against Williams are even more one-sided: Williams has won her last seven matches against Azarenka and the last eight against Sharapova.