Sharapova regained the sting on her backhand .
Sharapova stopped a three - game slide to close an impressive 6 - 4 , 6 - 4 win over Simona Halep at the WTA Finals .
Regaining the sting on her backhand , Sharapova stopped a three - game slide to close an impressive 6 - 4 , 6 - 4 win over Simona Halep at the WTA Finals .