SINGAPORE - Svetlana Kuznetsova and Agnieszka Radwanska came out as winners in their respective matches at the WTA Finals on Wednesday. The White Group was back in action from Singapore.

In the first match, Kuznetsova was forced to dig deep for the second consecutive match as she dispatched Karolina Pliskova 3-6, 6-2, 7-6. It was also the second straight match in which she rallied from a deficit to win a thrilling three-setter.

The Russian fell behind early in the match as the stoic and steady Pliskova controlled play. However, later in the first set, the Czech was forced to hold off a late run by Kuznetsova. After sprinting out to a 4-1 lead, Pliskova quickly found herself scrambling to hold on to her advantage. But after Kuznetsova broke serve to get back into the set, the world no. 5 quickly returned the favor and proceeded to serve out the set.

The script was flipped in the second set as Kuznetsova gained a 4-1 edge. She, then, held off a late attempt by Pliskova to battle back. But in a set in which each player broke serve four times, a tiebreak was needed to decide the match.

Kuznetsova quickly found herself in the driver’s seat in the tiebreak, earning a 6-3 edge. But Pliskova fought off three consecutive match points to level it. However, it was Kuznetsova who gained the decisive point as Pliskova served at 6-7 and was unable to capitalize on her serve.

“I felt the support of the crowd and I couldn't let anyone down,” said Kuznetsova. “So I had to fight.” With the win, she ran her 2016 record in three-set matches to 22-8.

Meanwhile, it was the defending champion Radwanska who defeated Garbine Muguruza 7-6, 6-3 in the second match.

In the opening set, neither player could find a rhythm in their service games as each was broken three times. With neither player gaining an advantage, play advanced to a tiebreak.  There, with the breaker even at 1-1, Radwanska seized control winning six consecutive points.

Muguruza would fight back in the second set, gaining a quick break of serve to take a 2-0 advantage. But the Pole would win six of the final seven games to cruise to the straight set win.

Radwanska’s clean play was key as Muguruza struck 37 unforced errors off of her big ground strokes, and she was only able to counter with 27 winners against the sound defensive skills of the veteran.

The 27-year old reflected on the match afterward, “There were a lot of ups and downs, obviously, and I think there were a lot of breaks as well so it was an open first set,” she said. “I'm just happy that I could play a good tie-break - that helped a lot! - and win in two sets. I've got great memories from last year, I was really feeling good on court. I really appreciated the Polish fans and Polish voices.”

With Wednesday’s White Group results, Kuznetsova clinched a spot in her first WTA Finals semifinals while Muguruza was eliminated from contention but meet the Russian in her next match. Pliskova will face Radwanska to determine Kuznetova's opponent in the semifinal.

On Thursday, Simona Halep will face Dominika Cibulkova and Angelique Kerber will square off against Madison Keys as Red Group play continues.