World number one Ashleigh Barty eased through to the semi-finals of the Cincinnati Open with victory over Barbora Krejcikova.
Australian Barty beat the Czech ninth seed 6-2 6-4, but had to recover from a break down in the second set.
The 25-year-old, two-time Grand Slam champion will face Angelique Kerber next after Petra Kvitova retired injured from their quarter-final.
Germany’s Kerber was leading 6-4 3-3 when she was awarded the win.
Czech world number 11 Kvitova later said she had been struggling with a “stomach issue” for several days.
In the men’s tournament, Russian top seed Daniil Medvedev crushed Spain’s Pablo Carreno Busta 6-1 6-1 to set up a semi-final meeting with compatriot Andrey Rublev.
Fourth seed Rublev progressed after defeating Frenchman Benoit Paire 6-2 3-6 6-3.
