Serena Williams continued her dominance over Caroline Wozniacki with a straight-sets win at the China Open.
Wozniacki had managed just one win in her previous six meetings with the world No 1 and she never looked like adding to that tally in Beijing.
And Williams, who has lost just four times on the WTA Tour this year, was barely troubled by the sixth seed as she registered a 6-1 6-4 victory.
Williams broke Wozniacki four times en route to victory, with the Dane struggling badly with her second serve.
Williams will now face the winner of Agnieszka Radwanska and Angelique Kerber in the semi-final.
The other half of the draw will see Petra Kvitova and Jelena Jankovic battle it out for a place in the final after hard-fought victories.
Kvitova, the No 9 seed, caused an upset as she ousted home favourite and ninth seed Li Na 4-6 6-2 6-4.
Eighth-seeded Jankovic also came from behind to progress, with the Serb beating Lucie Safarova 6-7 (7-3) 6-4 6-4.