Samantha Stosur has reached the last eight of the Cincinnati Masters with a three-sets victory over Li Na.
In a tight two-hour contest, the Australian had the marginally better serve to take the first set 6-4.
The 2011 French Open winner fought back and levelled the encounter by winning the second set 6-3.
Stosur served consistently throughout and claimed the final set 6-4 to set up a quarter-final match against Maria Sharapova.