Agnieszka Radwanska took a step closer to defending her WTA Finals title by advancing to the semifinals after a 7-5, 6-3 win against Karolina Pliskova.

In the first set, it was Pliskova who gained the early advantage and played to her strength. But after taking a 4-2 lead, Radwanska found a groove and won the next three games. And with Pliskova serving to stay in the set, the Pole quickly gained a decisive edge, broke serve and took the set.

Each player struggled during their service games in the second set and play went back and forth until Radwanska broke serve to even the set at 3-3. She would not lose another game and closed out the match.

Radwanska’s steady play and strong defending blunted the power of the Czech and she was successful redirecting the big groundstrokes to gain her own advantage. The result was 29 unforced errors off of Pliskova’s racket.

Radwanska summed up the result afterward, “I definitely knew I had to play my best tennis against her. She was showing only good tennis this week as well.”

Meanwhile, Pliskova would credit her opponent, “She also knew she has to win. She always beats me, so I just believed that she might miss in the close moments a little bit but she didn't. I think she just controlled the whole match.”

With the win, Radwanska will move on the play world no. 1 Angelique Kerber on Saturday.

In an earlier match, Garbine Muguruza finally broke through with a win in Singapore, defeating Svetlana Kuznetsova 3-6, 6-0, 6-1. However, Kuznetsova had already clinched a semifinal spot and will face Dominika Cibulkova on Saturday.