Angelique Kerber defeated US Open champion Naomi Osaka in three sets in the WTA Finals Red Group in Singapore to get her hopes of qualifying for the next stage back on track.

Kerber, who lost her opening match to Belgian Kiki Bertens, beat Osaka 6-4, 5-7, 6-4. Kerber will face Sloane Stephens in her final group match on Friday, with her qualification for the next round dependant upon the result.