Kim Clijsters cruised to an easy win over Daniela Hantuchova to reach the semi-finals of the Bank of the West Classic in Stanford.
The fourth-seeded Belgian brushed aside her Slovakian opponent 6-3 6-1.
Clijsters will now play Germany's Anna-Lena Groenefeld, who came back from a set down to beat sixth seed Nathalie Dechy of France 2-6 6-2 6-3.
Wimbledon champion Venus Williams will face Switzerland's Patty Schnyder in the other semi-final.
Williams beat Serbian seventh seed Jelena Jankovic 6-3 6-3, while Schnyder saw off Czech Iveta Benesova 6-2 6-1.