SINGAPORE (AFP) - Tennis' world No. 1 Serena Williams reached the WTA Finals semi-finals on Friday, when Simona Halep won the second set of her match against Ana Ivanovic.
Halep earned a reprieve for Williams, whom she stunned 6-0, 6-2 on Wednesday, and guaranteed top spot in the Red Group round robin when she took the second set 6-3.
Ivanovic won the first set but the result of the match is now immaterial to the final standings.
Win or lose the deciding set, Halep will play White Group runner-up Agnieska Radwanska in Saturday's semi-finals, while Williams takes on Caroline Wozniacki, who won all her matches against Radwanska, Petra Kvitova and Maria Sharapova.