World No.1 Ashleigh Barty has lost in straight sets to Aryna Sabalenka in the semi-finals of Wuhan Open in China.

The Australian top seed, chasing her fourth trophy of 2019, lost 7-5 6-4 on Friday to the Ukrainian defending champion and No.9 seed.

Barty was broken twice in the opening set. She clawed back one service break but, despite saving a number of set points, lost the opener.

Barty had a lengthy medical time-out after taking a 3-2 lead in the second set. It was not clear what impact that issue had on her performance.

In the second semi-final, two-time champion Petra Kvitova will square off against American Alison Riske, who had upset third-seeded Elina Svitolina in straight sets.

AAP