Radwanska bounces back against Muguruza

The Pole survived a topsy-turvy opening set before pulling away in the second for a 7-6 (7-1), 6-3 victory in the White Group clash.

As for Muguruza, her dramatic drop in form since winning the French Open earlier this year continues.

The two women were evenly matched in the first set, with neither able to carve out an advantage as they exchanged no less than six breaks of serve.

Every time Radwanska broke, Muguruza hit back with a break of her own to get back on level terms.

It was left to a tie-break to decide matters, and it was Radwanska who made the most of her opportunities, producing a superb lob and an overhead smash at 3-1, followed by a backhand winner to convert set point.

To Muguruza's credit she did not lie down, snatching the first break of the second set to lead 2-0, but Radwanska would find an extra level from there, winning six of the last seven games to wrap up the win in one hour and 38 minutes.

Earlier, Svetlana Kuznetsova outlasted Karolina Pliskova in a three-set thriller.

The Russian star earned her second win of the tournament when she came back from a set down to edge Pliskova 3-6, 6-2, 7-6 (8-6) in a touch over two hours to take a surprise lead over her favoured rivals in the White Group.

Pliskova enjoyed the stronger start, taking a 3-1 lead before Kuznetsova broke back. But the Czech had another break in her to take the opening set.

After winning the opening game, it looked as though it could be one-way traffic for Pliskova, but Kuznetsova rallied to four games in a row on her way to levelling the match. 

And so started what would turn out to be a mammoth final set lasting well over an hour.

Both players struggled to hold serve and after a fourth break from Kuznetsov, she forced a tiebreaker.

Kuznetsova took the momentum into the tiebreaker where she went 6-3 up. But a defiant Pliskova would save three match points to tie things up once more.

But Kuznetsova had one more powerful backhand to seal the win and take a giant leap towards the semi-finals in Singapore.