Simona Halep took a step nearer overhauling Garbine Muguruza as world number one when the Romanian raced into the semi-finals of the China Open on Friday.
Semi-final awaits Halep
The second-ranked Halep eased past Russia's unseeded Daria Kasatkina 6-2, 6-1 in 69 minutes in Beijing and will face compatriot Sorana Cirstea or Latvia's Jelena Ostapenko in the last four.
The Spaniard Muguruza's short stay at the top is under severe threat after she bowed out in the first round in the Chinese capital with a virus.
Halep is in red-hot form and claimed the scalp of former number one Maria Sharapova in the previous round -- beating the Russian at the eighth attempt.
Nadal keeping Spain number one
Third seed Grigor Dimitrov of Bulgaria was the first into the semi-finals of the men's draw when he battled past the Spaniard Roberto Bautista Agut 7-6 (7/5), 4-6, 6-2.
Dimitrov will play John Isner or world number one Rafael Nadal in the last four.