Samantha Stosur is one step closer to the end-of-year Championship final after beating Li Na to reach the semi-finals in Istanbul.
The world number seven recorded a 1-6 0-6 victory over the 29-year-old in the Sinan Erdem Dome in Turkey.
The two competitors headed into the clash on equal standings in the round robin group with both experiencing one victory and defeat.
The Australian, who has beaten her Chinese opponent in their last five meetings, started off the first set positively after winning a break to love over Li Na in the second game.
The 27-year-old raced to a four love lead in the opening set under 20 minutes and although the French Open winner claimed one game, Stosur managed to go on and establish a one-set lead in Turkey.
The US Open champion continued her onslaught to win the match in straight sets and come second behind Victoria Azarenka in the White Group of the WTA Championships.
